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| author | Michele Calgaro <michele.calgaro@yahoo.it> | 2024-05-28 10:17:01 +0900 |
|---|---|---|
| committer | Michele Calgaro <michele.calgaro@yahoo.it> | 2024-05-28 10:17:01 +0900 |
| commit | 5fffa30386502b5423e45c2ed5e6af756b11c7b4 (patch) | |
| tree | fa17e10b048e8e13433b861cbe98cf895b2324c7 /doc/html/ntqsqlcursor.html | |
| parent | 04913ce7a46fd027856e83a96205fdc388742a19 (diff) | |
| download | tqt-5fffa30386502b5423e45c2ed5e6af756b11c7b4.tar.gz tqt-5fffa30386502b5423e45c2ed5e6af756b11c7b4.zip | |
Rename nt* sql related files to equivalent tq*
Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>
Diffstat (limited to 'doc/html/ntqsqlcursor.html')
| -rw-r--r-- | doc/html/ntqsqlcursor.html | 761 |
1 files changed, 0 insertions, 761 deletions
diff --git a/doc/html/ntqsqlcursor.html b/doc/html/ntqsqlcursor.html deleted file mode 100644 index e0aa1ff2f..000000000 --- a/doc/html/ntqsqlcursor.html +++ /dev/null @@ -1,761 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> -<!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/src/sql/qsqlcursor.cpp:122 --> -<html> -<head> -<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> -<title>TQSqlCursor Class</title> -<style type="text/css"><!-- -fn { margin-left: 1cm; text-indent: -1cm; } -a:link { color: #004faf; text-decoration: none } -a:visited { color: #672967; text-decoration: none } -body { background: #ffffff; color: black; } ---></style> -</head> -<body> - -<table border="0" cellpadding="0" cellspacing="0" width="100%"> -<tr bgcolor="#E5E5E5"> -<td valign=center> - <a href="index.html"> -<font color="#004faf">Home</font></a> - | <a href="classes.html"> -<font color="#004faf">All Classes</font></a> - | <a href="mainclasses.html"> -<font color="#004faf">Main Classes</font></a> - | <a href="annotated.html"> -<font color="#004faf">Annotated</font></a> - | <a href="groups.html"> -<font color="#004faf">Grouped Classes</font></a> - | <a href="functions.html"> -<font color="#004faf">Functions</font></a> -</td> -<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>TQSqlCursor Class Reference<br><small>[<a href="sql.html">sql module</a>]</small></h1> - -<p>The TQSqlCursor class provides browsing and editing of SQL -tables and views. -<a href="#details">More...</a> -<p><tt>#include <<a href="qsqlcursor-h.html">ntqsqlcursor.h</a>></tt> -<p>Inherits <a href="ntqsqlrecord.html">TQSqlRecord</a> and <a href="ntqsqlquery.html">TQSqlQuery</a>. -<p>Inherited by <a href="ntqsqlselectcursor.html">TQSqlSelectCursor</a>. -<p><a href="qsqlcursor-members.html">List of all member functions.</a> -<h2>Public Members</h2> -<ul> -<li class=fn><a href="#TQSqlCursor"><b>TQSqlCursor</b></a> ( const TQString & name = TQString::null, bool autopopulate = TRUE, TQSqlDatabase * db = 0 )</li> -<li class=fn><a href="#TQSqlCursor-2"><b>TQSqlCursor</b></a> ( const TQSqlCursor & other )</li> -<li class=fn>TQSqlCursor & <a href="#operator-eq"><b>operator=</b></a> ( const TQSqlCursor & other )</li> -<li class=fn><a href="#~TQSqlCursor"><b>~TQSqlCursor</b></a> ()</li> -<li class=fn>enum <a href="#Mode-enum"><b>Mode</b></a> { ReadOnly = 0, Insert = 1, Update = 2, Delete = 4, Writable = 7 }</li> -<li class=fn>virtual TQSqlIndex <a href="#primaryIndex"><b>primaryIndex</b></a> ( bool setFromCursor = TRUE ) const</li> -<li class=fn>virtual TQSqlIndex <a href="#index"><b>index</b></a> ( const TQStringList & fieldNames ) const</li> -<li class=fn>TQSqlIndex <a href="#index-2"><b>index</b></a> ( const TQString & fieldName ) const</li> -<li class=fn>TQSqlIndex <a href="#index-3"><b>index</b></a> ( const char * fieldName ) const</li> -<li class=fn>virtual void <a href="#setPrimaryIndex"><b>setPrimaryIndex</b></a> ( const TQSqlIndex & idx )</li> -<li class=fn>virtual void <a href="#append"><b>append</b></a> ( const TQSqlFieldInfo & fieldInfo )</li> -<li class=fn>virtual void <a href="#insert"><b>insert</b></a> ( int pos, const TQSqlFieldInfo & fieldInfo )</li> -<li class=fn>virtual void <a href="#remove"><b>remove</b></a> ( int pos )</li> -<li class=fn>virtual void <a href="#clear"><b>clear</b></a> ()</li> -<li class=fn>virtual void <a href="#setGenerated"><b>setGenerated</b></a> ( const TQString & name, bool generated )</li> -<li class=fn>virtual void <a href="#setGenerated-2"><b>setGenerated</b></a> ( int i, bool generated )</li> -<li class=fn>virtual TQSqlRecord * <a href="#editBuffer"><b>editBuffer</b></a> ( bool copy = FALSE )</li> -<li class=fn>virtual TQSqlRecord * <a href="#primeInsert"><b>primeInsert</b></a> ()</li> -<li class=fn>virtual TQSqlRecord * <a href="#primeUpdate"><b>primeUpdate</b></a> ()</li> -<li class=fn>virtual TQSqlRecord * <a href="#primeDelete"><b>primeDelete</b></a> ()</li> -<li class=fn>virtual int <a href="#insert-2"><b>insert</b></a> ( bool invalidate = TRUE )</li> -<li class=fn>virtual int <a href="#update"><b>update</b></a> ( bool invalidate = TRUE )</li> -<li class=fn>virtual int <a href="#del"><b>del</b></a> ( bool invalidate = TRUE )</li> -<li class=fn>virtual void <a href="#setMode"><b>setMode</b></a> ( int mode )</li> -<li class=fn>int <a href="#mode"><b>mode</b></a> () const</li> -<li class=fn>virtual void <a href="#setCalculated"><b>setCalculated</b></a> ( const TQString & name, bool calculated )</li> -<li class=fn>bool <a href="#isCalculated"><b>isCalculated</b></a> ( const TQString & name ) const</li> -<li class=fn>virtual void <a href="#setTrimmed"><b>setTrimmed</b></a> ( const TQString & name, bool trim )</li> -<li class=fn>bool <a href="#isTrimmed"><b>isTrimmed</b></a> ( const TQString & name ) const</li> -<li class=fn>bool <a href="#isReadOnly"><b>isReadOnly</b></a> () const</li> -<li class=fn>bool <a href="#canInsert"><b>canInsert</b></a> () const</li> -<li class=fn>bool <a href="#canUpdate"><b>canUpdate</b></a> () const</li> -<li class=fn>bool <a href="#canDelete"><b>canDelete</b></a> () const</li> -<li class=fn>bool <a href="#select-2"><b>select</b></a> ()</li> -<li class=fn>bool <a href="#select-3"><b>select</b></a> ( const TQSqlIndex & sort )</li> -<li class=fn>bool <a href="#select-4"><b>select</b></a> ( const TQSqlIndex & filter, const TQSqlIndex & sort )</li> -<li class=fn>virtual bool <a href="#select"><b>select</b></a> ( const TQString & filter, const TQSqlIndex & sort = TQSqlIndex ( ) )</li> -<li class=fn>virtual void <a href="#setSort"><b>setSort</b></a> ( const TQSqlIndex & sort )</li> -<li class=fn>TQSqlIndex <a href="#sort"><b>sort</b></a> () const</li> -<li class=fn>virtual void <a href="#setFilter"><b>setFilter</b></a> ( const TQString & filter )</li> -<li class=fn>TQString <a href="#filter"><b>filter</b></a> () const</li> -<li class=fn>virtual void <a href="#setName"><b>setName</b></a> ( const TQString & name, bool autopopulate = TRUE )</li> -<li class=fn>TQString <a href="#name"><b>name</b></a> () const</li> -<li class=fn>bool <a href="#isNull"><b>isNull</b></a> ( int i ) const</li> -<li class=fn>bool <a href="#isNull-2"><b>isNull</b></a> ( const TQString & name ) const</li> -</ul> -<h2>Protected Members</h2> -<ul> -<li class=fn>virtual TQVariant <a href="#calculateField"><b>calculateField</b></a> ( const TQString & name )</li> -<li class=fn>virtual int <a href="#update-2"><b>update</b></a> ( const TQString & filter, bool invalidate = TRUE )</li> -<li class=fn>virtual int <a href="#del-2"><b>del</b></a> ( const TQString & filter, bool invalidate = TRUE )</li> -<li class=fn>virtual TQString <a href="#toString-3"><b>toString</b></a> ( const TQString & prefix, TQSqlField * field, const TQString & fieldSep ) const</li> -<li class=fn>virtual TQString <a href="#toString"><b>toString</b></a> ( TQSqlRecord * rec, const TQString & prefix, const TQString & fieldSep, const TQString & sep ) const</li> -<li class=fn>virtual TQString <a href="#toString-4"><b>toString</b></a> ( const TQSqlIndex & i, TQSqlRecord * rec, const TQString & prefix, const TQString & fieldSep, const TQString & sep ) const</li> -</ul> -<hr><a name="details"></a><h2>Detailed Description</h2> - - -The TQSqlCursor class provides browsing and editing of SQL -tables and views. -<p> - -<p> A TQSqlCursor is a database record (see <a href="ntqsqlrecord.html">TQSqlRecord</a>) that -corresponds to a table or view within an SQL database (see <a href="ntqsqldatabase.html">TQSqlDatabase</a>). There are two buffers in a cursor, one used for -browsing and one used for editing records. Each buffer contains a -list of fields which correspond to the fields in the table or -view. -<p> When positioned on a valid record, the browse buffer contains the -values of the current record's fields from the database. The edit -buffer is separate, and is used for editing existing records and -inserting new records. -<p> For browsing data, a cursor must first <a href="#select">select</a>() data from the -database. After a successful select() the cursor is active -(<a href="ntqsqlquery.html#isActive">isActive</a>() returns TRUE), but is initially not positioned on a -valid record (<a href="ntqsqlquery.html#isValid">isValid</a>() returns FALSE). To position the cursor on -a valid record, use one of the navigation functions, <a href="ntqsqlquery.html#next">next</a>(), -<a href="ntqsqlquery.html#prev">prev</a>(), <a href="ntqsqlquery.html#first">first</a>(), <a href="ntqsqlquery.html#last">last</a>(), or <a href="ntqsqlquery.html#seek">seek</a>(). Once positioned on a valid -record, data can be retrieved from the browse buffer using -<a href="ntqsqlquery.html#value">value</a>(). If a navigation function is not successful, it returns -FALSE, the cursor will no longer be positioned on a valid record -and the values returned by value() are undefined. -<p> For example: -<p> - -<pre> TQSqlCursor cur( "staff" ); // Specify the table/view name - <a name="x2178"></a> cur.<a href="#select">select</a>(); // We'll retrieve every record - while ( cur.<a href="ntqsqlquery.html#next">next</a>() ) { - <a name="x2179"></a> <a href="ntqapplication.html#qDebug">tqDebug</a>( cur.<a href="ntqsqlquery.html#value">value</a>( "id" ).toString() + ": " + - cur.<a href="ntqsqlquery.html#value">value</a>( "surname" ).toString() + " " + - cur.<a href="ntqsqlquery.html#value">value</a>( "salary" ).toString() ); - } -</pre> -<p> In the above example, a cursor is created specifying a table or -view name in the database. Then, <a href="#select">select</a>() is called, which can be -optionally parameterised to filter and order the records -retrieved. Each record in the cursor is retrieved using <a href="ntqsqlquery.html#next">next</a>(). -When next() returns FALSE, there are no more records to process, -and the loop terminates. -<p> For editing records (rows of data), a cursor contains a separate -edit buffer which is independent of the fields used when browsing. -The functions <a href="#insert">insert</a>(), <a href="#update">update</a>() and <a href="#del">del</a>() operate on the edit -buffer. This allows the cursor to be repositioned to other -records while simultaneously maintaining a separate buffer for -edits. You can get a pointer to the edit buffer using -<a href="#editBuffer">editBuffer</a>(). The <a href="#primeInsert">primeInsert</a>(), <a href="#primeUpdate">primeUpdate</a>() and <a href="#primeDelete">primeDelete</a>() -functions also return a pointer to the edit buffer and prepare it -for insert, update and delete respectively. Edit operations only -affect a single row at a time. Note that update() and del() -require that the table or view contain a <a href="#primaryIndex">primaryIndex</a>() to ensure -that edit operations affect a unique record within the database. -<p> For example: -<p> - -<pre> TQSqlCursor cur( "prices" ); - <a name="x2200"></a> cur.<a href="#select">select</a>( "id=202" ); - if ( cur.<a href="ntqsqlquery.html#next">next</a>() ) { - <a name="x2199"></a> <a href="ntqsqlrecord.html">TQSqlRecord</a> *buffer = cur.<a href="#primeUpdate">primeUpdate</a>(); - <a name="x2204"></a> double price = buffer-><a href="ntqsqlrecord.html#value">value</a>( "price" ).toDouble(); - double newprice = price * 1.05; - <a name="x2203"></a> buffer-><a href="ntqsqlrecord.html#setValue">setValue</a>( "price", newprice ); - <a name="x2201"></a> cur.<a href="#update">update</a>(); - } -</pre> -<p> To edit an existing database record, first move to the record you -wish to update. Call <a href="#primeUpdate">primeUpdate</a>() to get the pointer to the -cursor's edit buffer. Then use this pointer to modify the values -in the edit buffer. Finally, call <a href="#update">update</a>() to save the changes to -the database. The values in the edit buffer will be used to -locate the appropriate record when updating the database (see -<a href="#primaryIndex">primaryIndex</a>()). -<p> Similarly, when deleting an existing database record, first move -to the record you wish to delete. Then, call <a href="#primeDelete">primeDelete</a>() to get -the pointer to the edit buffer. Finally, call <a href="#del">del</a>() to delete the -record from the database. Again, the values in the edit buffer -will be used to locate and delete the appropriate record. -<p> To insert a new record, call <a href="#primeInsert">primeInsert</a>() to get the pointer to -the edit buffer. Use this pointer to populate the edit buffer -with new values and then <a href="#insert">insert</a>() the record into the database. -<p> After calling insert(), update() or del(), the cursor is no longer -positioned on a valid record and can no longer be navigated -(<a href="ntqsqlquery.html#isValid">isValid</a>() return FALSE). The reason for this is that any changes -made to the database will not be visible until <a href="#select">select</a>() is called -to refresh the cursor. You can change this behavior by passing -FALSE to insert(), <a href="#update">update</a>() or del() which will prevent the cursor -from becoming invalid. The edits will still not be visible when -navigating the cursor until select() is called. -<p> TQSqlCursor contains virtual methods which allow editing behavior -to be customized by subclasses. This allows custom cursors to be -created that encapsulate the editing behavior of a database table -for an entire application. For example, a cursor can be customized -to always auto-number primary index fields, or provide fields with -suitable default values, when inserting new records. TQSqlCursor -generates SQL statements which are sent to the database engine; -you can control which fields are included in these statements -using <a href="#setGenerated">setGenerated</a>(). -<p> Note that TQSqlCursor does not inherit from <a href="tqobject.html">TQObject</a>. This means -that you are responsible for destroying instances of this class -yourself. However if you create a TQSqlCursor and use it in a -<a href="ntqdatatable.html">TQDataTable</a>, <a href="ntqdatabrowser.html">TQDataBrowser</a> or a <a href="ntqdataview.html">TQDataView</a> these classes will -usually take ownership of the cursor and destroy it when they -don't need it anymore. The documentation for <a href="ntqdatatable.html">TQDataTable</a>, -<a href="ntqdatabrowser.html">TQDataBrowser</a> and <a href="ntqdataview.html">TQDataView</a> explicitly states which calls take -ownership of the cursor. -<p>See also <a href="database.html">Database Classes</a>. - -<hr><h2>Member Type Documentation</h2> -<h3 class=fn><a name="Mode-enum"></a>TQSqlCursor::Mode</h3> - -<p> This enum type describes how TQSqlCursor operates on records in the -database. -<ul> -<li><tt>TQSqlCursor::ReadOnly</tt> - the cursor can only SELECT records from the -database. -<li><tt>TQSqlCursor::Insert</tt> - the cursor can INSERT records into the database. -<li><tt>TQSqlCursor::Update</tt> - the cursor can UPDATE records in the database. -<li><tt>TQSqlCursor::Delete</tt> - the cursor can DELETE records from the database. -<li><tt>TQSqlCursor::Writable</tt> - the cursor can INSERT, UPDATE and DELETE records -in the database. -</ul> -<hr><h2>Member Function Documentation</h2> -<h3 class=fn><a name="TQSqlCursor"></a>TQSqlCursor::TQSqlCursor ( const <a href="ntqstring.html">TQString</a> & name = TQString::null, bool autopopulate = TRUE, <a href="ntqsqldatabase.html">TQSqlDatabase</a> * db = 0 ) -</h3> -Constructs a cursor on database <em>db</em> using table or view <em>name</em>. -<p> If <em>autopopulate</em> is TRUE (the default), the <em>name</em> of the -cursor must correspond to an existing table or view name in the -database so that field information can be automatically created. -If the table or view does not exist, the cursor will not be -functional. -<p> The cursor is created with an initial mode of TQSqlCursor::Writable -(meaning that records can be inserted, updated or deleted using -the cursor). If the cursor does not have a unique primary index, -update and deletes cannot be performed. -<p> Note that <em>autopopulate</em> refers to populating the cursor with -meta-data, e.g. the names of the table's fields, not with -retrieving data. The <a href="#select">select</a>() function is used to populate the -cursor with data. -<p> <p>See also <a href="#setName">setName</a>() and <a href="#setMode">setMode</a>(). - -<h3 class=fn><a name="TQSqlCursor-2"></a>TQSqlCursor::TQSqlCursor ( const <a href="ntqsqlcursor.html">TQSqlCursor</a> & other ) -</h3> -Constructs a copy of <em>other</em>. - -<h3 class=fn><a name="~TQSqlCursor"></a>TQSqlCursor::~TQSqlCursor () -</h3> -Destroys the object and frees any allocated resources. - -<h3 class=fn>void <a name="append"></a>TQSqlCursor::append ( const <a href="qsqlfieldinfo.html">TQSqlFieldInfo</a> & fieldInfo )<tt> [virtual]</tt> -</h3> -Append a copy of field <em>fieldInfo</em> to the end of the cursor. Note -that all references to the cursor edit buffer become invalidated. - -<h3 class=fn><a href="ntqvariant.html">TQVariant</a> <a name="calculateField"></a>TQSqlCursor::calculateField ( const <a href="ntqstring.html">TQString</a> & name )<tt> [virtual protected]</tt> -</h3> -Protected virtual function which is called whenever a field needs -to be calculated. If calculated fields are being used, derived -classes must reimplement this function and return the appropriate -value for field <em>name</em>. The default implementation returns an -invalid <a href="ntqvariant.html">TQVariant</a>. -<p> <p>See also <a href="#setCalculated">setCalculated</a>(). - -<p>Examples: <a href="sql.html#x2259">sql/overview/subclass3/main.cpp</a> and <a href="sql.html#x2263">sql/overview/subclass4/main.cpp</a>. -<h3 class=fn>bool <a name="canDelete"></a>TQSqlCursor::canDelete () const -</h3> -Returns TRUE if the cursor will perform deletes; otherwise returns -FALSE. -<p> <p>See also <a href="#setMode">setMode</a>(). - -<h3 class=fn>bool <a name="canInsert"></a>TQSqlCursor::canInsert () const -</h3> -Returns TRUE if the cursor will perform inserts; otherwise returns -FALSE. -<p> <p>See also <a href="#setMode">setMode</a>(). - -<h3 class=fn>bool <a name="canUpdate"></a>TQSqlCursor::canUpdate () const -</h3> -Returns TRUE if the cursor will perform updates; otherwise returns -FALSE. -<p> <p>See also <a href="#setMode">setMode</a>(). - -<h3 class=fn>void <a name="clear"></a>TQSqlCursor::clear ()<tt> [virtual]</tt> -</h3> -Removes all fields from the cursor. Note that all references to -the cursor edit buffer become invalidated. - -<p>Reimplemented from <a href="ntqsqlrecord.html#clear">TQSqlRecord</a>. -<h3 class=fn>int <a name="del"></a>TQSqlCursor::del ( bool invalidate = TRUE )<tt> [virtual]</tt> -</h3> -Deletes a record from the database using the cursor's primary -index and the contents of the cursor edit buffer. Returns the -number of records which were deleted. -For error information, use <a href="ntqsqlquery.html#lastError">lastError</a>(). -<p> Only records which meet the filter criteria specified by the -cursor's primary index are deleted. If the cursor does not contain -a primary index, no delete is performed and 0 is returned. If <em>invalidate</em> is TRUE (the default), the current cursor can no longer -be navigated. A new <a href="#select">select</a>() call must be made before you can move -to a valid record. For example: -<p> - -<pre> TQSqlCursor cur( "prices" ); - <a name="x2207"></a> cur.<a href="#select">select</a>( "id=999" ); - <a name="x2208"></a> if ( cur.<a href="ntqsqlquery.html#next">next</a>() ) { - <a name="x2206"></a> cur.<a href="#primeDelete">primeDelete</a>(); - <a name="x2205"></a> cur.<a href="#del">del</a>(); - } -</pre> -<p> In the above example, a cursor is created on the 'prices' table -and positioned to the record to be deleted. First <a href="#primeDelete">primeDelete</a>() is -called to populate the edit buffer with the current cursor values, -e.g. with an id of 999, and then <a href="#del">del</a>() is called to actually -delete the record from the database. Remember: all edit operations -(<a href="#insert">insert</a>(), <a href="#update">update</a>() and delete()) operate on the contents of the -cursor edit buffer and not on the contents of the cursor itself. -<p> <p>See also <a href="#primeDelete">primeDelete</a>(), <a href="#setMode">setMode</a>(), and <a href="ntqsqlquery.html#lastError">lastError</a>(). - -<p>Example: <a href="sql.html#x2205">sql/overview/delete/main.cpp</a>. -<h3 class=fn>int <a name="del-2"></a>TQSqlCursor::del ( const <a href="ntqstring.html">TQString</a> & filter, bool invalidate = TRUE )<tt> [virtual protected]</tt> -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Deletes the current cursor record from the database using the -filter <em>filter</em>. Only records which meet the filter criteria are -deleted. Returns the number of records which were deleted. If <em>invalidate</em> is TRUE (the default), the current cursor can no longer -be navigated. A new <a href="#select">select</a>() call must be made before you can move -to a valid record. For error information, use <a href="ntqsqlquery.html#lastError">lastError</a>(). -<p> The <em>filter</em> is an SQL <tt>WHERE</tt> clause, e.g. <tt>id=500</tt>. -<p> <p>See also <a href="#setMode">setMode</a>() and <a href="ntqsqlquery.html#lastError">lastError</a>(). - -<h3 class=fn><a href="ntqsqlrecord.html">TQSqlRecord</a> * <a name="editBuffer"></a>TQSqlCursor::editBuffer ( bool copy = FALSE )<tt> [virtual]</tt> -</h3> -Returns the current internal edit buffer. If <em>copy</em> is TRUE (the -default is FALSE), the current cursor field values are first -copied into the edit buffer. The edit buffer is valid as long as -the cursor remains valid. The cursor retains ownership of the -returned pointer, so it must not be deleted or modified. -<p> <p>See also <a href="#primeInsert">primeInsert</a>(), <a href="#primeUpdate">primeUpdate</a>(), and <a href="#primeDelete">primeDelete</a>(). - -<h3 class=fn><a href="ntqstring.html">TQString</a> <a name="filter"></a>TQSqlCursor::filter () const -</h3> -Returns the current filter, or an empty string if there is no -current filter. - -<h3 class=fn><a href="ntqsqlindex.html">TQSqlIndex</a> <a name="index"></a>TQSqlCursor::index ( const <a href="ntqstringlist.html">TQStringList</a> & fieldNames ) const<tt> [virtual]</tt> -</h3> -Returns an index composed of <em>fieldNames</em>, all in ASCending -order. Note that all field names must exist in the cursor, -otherwise an empty index is returned. -<p> <p>See also <a href="ntqsqlindex.html">TQSqlIndex</a>. - -<p>Examples: <a href="sql.html#x2188">sql/overview/extract/main.cpp</a>, <a href="sql.html#x2181">sql/overview/order1/main.cpp</a>, <a href="sql.html#x2184">sql/overview/order2/main.cpp</a>, and <a href="sql.html#x2241">sql/overview/table3/main.cpp</a>. -<h3 class=fn><a href="ntqsqlindex.html">TQSqlIndex</a> <a name="index-2"></a>TQSqlCursor::index ( const <a href="ntqstring.html">TQString</a> & fieldName ) const -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Returns an index based on <em>fieldName</em>. - -<h3 class=fn><a href="ntqsqlindex.html">TQSqlIndex</a> <a name="index-3"></a>TQSqlCursor::index ( const char * fieldName ) const -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Returns an index based on <em>fieldName</em>. - -<h3 class=fn>void <a name="insert"></a>TQSqlCursor::insert ( int pos, const <a href="qsqlfieldinfo.html">TQSqlFieldInfo</a> & fieldInfo )<tt> [virtual]</tt> -</h3> -Insert a copy of <em>fieldInfo</em> at position <em>pos</em>. If a field -already exists at <em>pos</em>, it is removed. Note that all references -to the cursor edit buffer become invalidated. - -<p>Examples: <a href="sql.html#x2194">sql/overview/insert/main.cpp</a> and <a href="ntqsqlcursor.html#x2446">sql/overview/insert2/main.cpp</a>. -<h3 class=fn>int <a name="insert-2"></a>TQSqlCursor::insert ( bool invalidate = TRUE )<tt> [virtual]</tt> -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Inserts the current contents of the cursor's edit record buffer -into the database, if the cursor allows inserts. Returns the -number of rows affected by the insert. For error information, use -<a href="ntqsqlquery.html#lastError">lastError</a>(). -<p> If <em>invalidate</em> is TRUE (the default), the cursor will no longer -be positioned on a valid record and can no longer be navigated. A -new <a href="#select">select</a>() call must be made before navigating to a valid -record. -<p> - -<pre> TQSqlCursor cur( "prices" ); - <a name="x2447"></a> <a href="ntqsqlrecord.html">TQSqlRecord</a> *buffer = cur.<a href="#primeInsert">primeInsert</a>(); - <a name="x2448"></a> buffer-><a href="ntqsqlrecord.html#setValue">setValue</a>( "id", 53981 ); - buffer-><a href="ntqsqlrecord.html#setValue">setValue</a>( "name", "Thingy" ); - buffer-><a href="ntqsqlrecord.html#setValue">setValue</a>( "price", 105.75 ); - <a name="x2446"></a> cur.<a href="#insert">insert</a>(); -</pre> -<p> In the above example, a cursor is created on the 'prices' table -and a pointer to the insert buffer is acquired using <a href="#primeInsert">primeInsert</a>(). -Each field's value is set to the desired value and then <a href="#insert">insert</a>() -is called to insert the data into the database. Remember: all edit -operations (insert(), <a href="#update">update</a>() and delete()) operate on the -contents of the cursor edit buffer and not on the contents of the -cursor itself. -<p> <p>See also <a href="#setMode">setMode</a>() and <a href="ntqsqlquery.html#lastError">lastError</a>(). - -<h3 class=fn>bool <a name="isCalculated"></a>TQSqlCursor::isCalculated ( const <a href="ntqstring.html">TQString</a> & name ) const -</h3> -Returns TRUE if the field <em>name</em> exists and is calculated; -otherwise returns FALSE. -<p> <p>See also <a href="#setCalculated">setCalculated</a>(). - -<h3 class=fn>bool <a name="isNull"></a>TQSqlCursor::isNull ( int i ) const -</h3> -Returns TRUE if the field <em>i</em> is NULL or if there is no field at -position <em>i</em>; otherwise returns FALSE. -<p> This is the same as calling <a href="ntqsqlrecord.html#isNull">TQSqlRecord::isNull</a>( <em>i</em> ) - -<h3 class=fn>bool <a name="isNull-2"></a>TQSqlCursor::isNull ( const <a href="ntqstring.html">TQString</a> & name ) const -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Returns TRUE if the field called <em>name</em> is NULL or if there is no -field called <em>name</em>; otherwise returns FALSE. -<p> This is the same as calling <a href="ntqsqlrecord.html#isNull">TQSqlRecord::isNull</a>( <em>name</em> ) - -<h3 class=fn>bool <a name="isReadOnly"></a>TQSqlCursor::isReadOnly () const -</h3> -Returns TRUE if the cursor is read-only; otherwise returns FALSE. -The default is FALSE. Read-only cursors cannot be edited using -<a href="#insert">insert</a>(), <a href="#update">update</a>() or <a href="#del">del</a>(). -<p> <p>See also <a href="#setMode">setMode</a>(). - -<h3 class=fn>bool <a name="isTrimmed"></a>TQSqlCursor::isTrimmed ( const <a href="ntqstring.html">TQString</a> & name ) const -</h3> -Returns TRUE if the field <em>name</em> exists and is trimmed; otherwise -returns FALSE. -<p> When a trimmed field of type string or cstring is read from the -database any trailing (right-most) spaces are removed. -<p> <p>See also <a href="#setTrimmed">setTrimmed</a>(). - -<h3 class=fn>int <a name="mode"></a>TQSqlCursor::mode () const -</h3> -Returns the current cursor mode. -<p> <p>See also <a href="#setMode">setMode</a>(). - -<h3 class=fn><a href="ntqstring.html">TQString</a> <a name="name"></a>TQSqlCursor::name () const -</h3> -Returns the name of the cursor. - -<h3 class=fn><a href="ntqsqlcursor.html">TQSqlCursor</a> & <a name="operator-eq"></a>TQSqlCursor::operator= ( const <a href="ntqsqlcursor.html">TQSqlCursor</a> & other ) -</h3> -Sets the cursor equal to <em>other</em>. - -<h3 class=fn><a href="ntqsqlindex.html">TQSqlIndex</a> <a name="primaryIndex"></a>TQSqlCursor::primaryIndex ( bool setFromCursor = TRUE ) const<tt> [virtual]</tt> -</h3> -Returns the primary index associated with the cursor as defined in -the database, or an empty index if there is no primary index. If -<em>setFromCursor</em> is TRUE (the default), the index fields are -populated with the corresponding values in the cursor's current -record. - -<h3 class=fn><a href="ntqsqlrecord.html">TQSqlRecord</a> * <a name="primeDelete"></a>TQSqlCursor::primeDelete ()<tt> [virtual]</tt> -</h3> -This function primes the edit buffer's field values for delete and -returns the edit buffer. The default implementation copies the -field values from the current cursor record into the edit buffer -(therefore, this function is equivalent to calling <a href="#editBuffer">editBuffer</a>( -TRUE ) ). The cursor retains ownership of the returned pointer, so -it must not be deleted or modified. -<p> <p>See also <a href="#editBuffer">editBuffer</a>() and <a href="#del">del</a>(). - -<p>Example: <a href="sql.html#x2206">sql/overview/delete/main.cpp</a>. -<h3 class=fn><a href="ntqsqlrecord.html">TQSqlRecord</a> * <a name="primeInsert"></a>TQSqlCursor::primeInsert ()<tt> [virtual]</tt> -</h3> -This function primes the edit buffer's field values for insert and -returns the edit buffer. The default implementation clears all -field values in the edit buffer. The cursor retains ownership of -the returned pointer, so it must not be deleted or modified. -<p> <p>See also <a href="#editBuffer">editBuffer</a>() and <a href="#insert">insert</a>(). - -<p>Examples: <a href="sql.html#x2195">sql/overview/insert/main.cpp</a>, <a href="ntqsqlcursor.html#x2447">sql/overview/insert2/main.cpp</a>, <a href="sql.html#x2267">sql/overview/subclass5/main.cpp</a>, and <a href="sqltable-example.html#x2453">sql/sqltable/main.cpp</a>. -<h3 class=fn><a href="ntqsqlrecord.html">TQSqlRecord</a> * <a name="primeUpdate"></a>TQSqlCursor::primeUpdate ()<tt> [virtual]</tt> -</h3> -This function primes the edit buffer's field values for update and -returns the edit buffer. The default implementation copies the -field values from the current cursor record into the edit buffer -(therefore, this function is equivalent to calling <a href="#editBuffer">editBuffer</a>( -TRUE ) ). The cursor retains ownership of the returned pointer, so -it must not be deleted or modified. -<p> <p>See also <a href="#editBuffer">editBuffer</a>() and <a href="#update">update</a>(). - -<p>Examples: <a href="sql.html#x2236">sql/overview/custom1/main.cpp</a>, <a href="sql.html#x2223">sql/overview/form1/main.cpp</a>, and <a href="sql.html#x2199">sql/overview/update/main.cpp</a>. -<h3 class=fn>void <a name="remove"></a>TQSqlCursor::remove ( int pos )<tt> [virtual]</tt> -</h3> -Removes the field at <em>pos</em>. If <em>pos</em> does not exist, nothing -happens. Note that all references to the cursor edit buffer become -invalidated. - -<p>Reimplemented from <a href="ntqsqlrecord.html#remove">TQSqlRecord</a>. -<h3 class=fn>bool <a name="select"></a>TQSqlCursor::select ( const <a href="ntqstring.html">TQString</a> & filter, const <a href="ntqsqlindex.html">TQSqlIndex</a> & sort = TQSqlIndex ( ) )<tt> [virtual]</tt> -</h3> -Selects all fields in the cursor from the database matching the -filter criteria <em>filter</em>. The data is returned in the order -specified by the index <em>sort</em>. Returns TRUE if the data was -successfully selected; otherwise returns FALSE. -<p> The <em>filter</em> is a string containing a SQL <tt>WHERE</tt> clause but -without the 'WHERE' keyword. The cursor is initially positioned at -an invalid row after this function is called. To move to a valid -row, use <a href="ntqsqlquery.html#seek">seek</a>(), <a href="ntqsqlquery.html#first">first</a>(), <a href="ntqsqlquery.html#last">last</a>(), <a href="ntqsqlquery.html#prev">prev</a>() or <a href="ntqsqlquery.html#next">next</a>(). -<p> Example: -<pre> - TQSqlCursor cur( "Employee" ); // Use the Employee table or view - cur.<a href="#select">select</a>( "deptno=10" ); // select all records in department 10 - while( cur.<a href="ntqsqlquery.html#next">next</a>() ) { - ... // process data - } - ... - // select records in other departments, ordered by department number - cur.<a href="#select">select</a>( "deptno>10", cur.<a href="#index">index</a>( "deptno" ) ); - ... - </pre> - -<p> The filter will apply to any subsequent <a href="#select">select</a>() calls that do not -explicitly specify another filter. Similarly the sort will apply -to any subsequent select() calls that do not explicitly specify -another sort. -<p> <pre> - TQSqlCursor cur( "Employee" ); - cur.<a href="#select">select</a>( "deptno=10" ); // select all records in department 10 - while( cur.<a href="ntqsqlquery.html#next">next</a>() ) { - ... // process data - } - ... - cur.<a href="#select">select</a>(); // re-selects all records in department 10 - ... - </pre> - -<p> -<p>Examples: <a href="sql.html#x2207">sql/overview/delete/main.cpp</a>, <a href="sql.html#x2189">sql/overview/extract/main.cpp</a>, <a href="sql.html#x2182">sql/overview/order1/main.cpp</a>, <a href="sql.html#x2185">sql/overview/order2/main.cpp</a>, <a href="sql.html#x2178">sql/overview/retrieve2/main.cpp</a>, <a href="sql.html#x2242">sql/overview/table3/main.cpp</a>, and <a href="sql.html#x2200">sql/overview/update/main.cpp</a>. -<h3 class=fn>bool <a name="select-2"></a>TQSqlCursor::select () -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Selects all fields in the cursor from the database. The rows are -returned in the order specified by the last call to <a href="#setSort">setSort</a>() or -the last call to <a href="#select">select</a>() that specified a sort, whichever is the -most recent. If there is no current sort, the order in which the -rows are returned is undefined. The records are filtered according -to the filter specified by the last call to <a href="#setFilter">setFilter</a>() or the -last call to select() that specified a filter, whichever is the -most recent. If there is no current filter, all records are -returned. The cursor is initially positioned at an invalid row. To -move to a valid row, use <a href="ntqsqlquery.html#seek">seek</a>(), <a href="ntqsqlquery.html#first">first</a>(), <a href="ntqsqlquery.html#last">last</a>(), <a href="ntqsqlquery.html#prev">prev</a>() or -<a href="ntqsqlquery.html#next">next</a>(). -<p> <p>See also <a href="#setSort">setSort</a>() and <a href="#setFilter">setFilter</a>(). - -<h3 class=fn>bool <a name="select-3"></a>TQSqlCursor::select ( const <a href="ntqsqlindex.html">TQSqlIndex</a> & sort ) -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Selects all fields in the cursor from the database. The data is -returned in the order specified by the index <em>sort</em>. The records -are filtered according to the filter specified by the last call to -<a href="#setFilter">setFilter</a>() or the last call to <a href="#select">select</a>() that specified a filter, -whichever is the most recent. The cursor is initially positioned -at an invalid row. To move to a valid row, use <a href="ntqsqlquery.html#seek">seek</a>(), <a href="ntqsqlquery.html#first">first</a>(), -<a href="ntqsqlquery.html#last">last</a>(), <a href="ntqsqlquery.html#prev">prev</a>() or <a href="ntqsqlquery.html#next">next</a>(). - -<h3 class=fn>bool <a name="select-4"></a>TQSqlCursor::select ( const <a href="ntqsqlindex.html">TQSqlIndex</a> & filter, const <a href="ntqsqlindex.html">TQSqlIndex</a> & sort ) -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Selects all fields in the cursor matching the filter index <em>filter</em>. The data is returned in the order specified by the index -<em>sort</em>. The <em>filter</em> index works by constructing a WHERE clause -using the names of the fields from the <em>filter</em> and their values -from the current cursor record. The cursor is initially positioned -at an invalid row. To move to a valid row, use <a href="ntqsqlquery.html#seek">seek</a>(), <a href="ntqsqlquery.html#first">first</a>(), -<a href="ntqsqlquery.html#last">last</a>(), <a href="ntqsqlquery.html#prev">prev</a>() or <a href="ntqsqlquery.html#next">next</a>(). This function is useful, for example, -for retrieving data based upon a table's primary index: -<p> <pre> - TQSqlCursor cur( "Employee" ); - <a href="ntqsqlindex.html">TQSqlIndex</a> pk = cur.<a href="#primaryIndex">primaryIndex</a>(); - cur.<a href="ntqsqlrecord.html#setValue">setValue</a>( "id", 10 ); - cur.<a href="#select">select</a>( pk, pk ); // generates "SELECT ... FROM Employee WHERE id=10 ORDER BY id" - ... - </pre> - -<p> In this example the <a href="ntqsqlindex.html">TQSqlIndex</a>, pk, is used for two different -purposes. When used as the filter (first) argument, the field -names it contains are used to construct the WHERE clause, each set -to the current cursor value, <tt>WHERE id=10</tt>, in this case. When -used as the sort (second) argument the field names it contains are -used for the ORDER BY clause, <tt>ORDER BY id</tt> in this example. - -<h3 class=fn>void <a name="setCalculated"></a>TQSqlCursor::setCalculated ( const <a href="ntqstring.html">TQString</a> & name, bool calculated )<tt> [virtual]</tt> -</h3> -Sets field <em>name</em> to <em>calculated</em>. If the field <em>name</em> does not -exist, nothing happens. The value of a calculated field is set by -the <a href="#calculateField">calculateField</a>() virtual function which you must reimplement -(or the field value will be an invalid <a href="ntqvariant.html">TQVariant</a>). Calculated -fields do not appear in generated SQL statements sent to the -database. -<p> <p>See also <a href="#calculateField">calculateField</a>() and <a href="ntqsqlrecord.html#setGenerated">TQSqlRecord::setGenerated</a>(). - -<h3 class=fn>void <a name="setFilter"></a>TQSqlCursor::setFilter ( const <a href="ntqstring.html">TQString</a> & filter )<tt> [virtual]</tt> -</h3> -Sets the current filter to <em>filter</em>. Note that no new records are -selected. To select new records, use <a href="#select">select</a>(). The <em>filter</em> will -apply to any subsequent select() calls that do not explicitly -specify a filter. -<p> The filter is a SQL <tt>WHERE</tt> clause without the keyword 'WHERE', -e.g. <tt>name='Dave'</tt> which will be processed by the DBMS. - -<h3 class=fn>void <a name="setGenerated"></a>TQSqlCursor::setGenerated ( const <a href="ntqstring.html">TQString</a> & name, bool generated )<tt> [virtual]</tt> -</h3> -Sets the generated flag for the field <em>name</em> to <em>generated</em>. If -the field does not exist, nothing happens. Only fields that have -<em>generated</em> set to TRUE are included in the SQL that is -generated by <a href="#insert">insert</a>(), <a href="#update">update</a>() or <a href="#del">del</a>(). -<p> <p>See also <a href="ntqsqlrecord.html#isGenerated">isGenerated</a>(). - -<p>Reimplemented from <a href="ntqsqlrecord.html#setGenerated">TQSqlRecord</a>. -<h3 class=fn>void <a name="setGenerated-2"></a>TQSqlCursor::setGenerated ( int i, bool generated )<tt> [virtual]</tt> -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Sets the generated flag for the field <em>i</em> to <em>generated</em>. -<p> <p>See also <a href="ntqsqlrecord.html#isGenerated">isGenerated</a>(). - -<p>Reimplemented from <a href="ntqsqlrecord.html#setGenerated-2">TQSqlRecord</a>. -<h3 class=fn>void <a name="setMode"></a>TQSqlCursor::setMode ( int mode )<tt> [virtual]</tt> -</h3> -Sets the cursor mode to <em>mode</em>. This value can be an OR'ed -combination of <a href="#Mode-enum">TQSqlCursor::Mode</a> values. The default mode for a -cursor is <a href="#Mode-enum">TQSqlCursor::Writable</a>. -<p> <pre> - TQSqlCursor cur( "Employee" ); - cur.<a href="#setMode">setMode</a>( TQSqlCursor::<a href="#Mode-enum">Writable</a> ); // allow insert/update/delete - ... - cur.<a href="#setMode">setMode</a>( TQSqlCursor::<a href="#Mode-enum">Insert</a> | TQSqlCursor::<a href="#Mode-enum">Update</a> ); // allow inserts and updates only - ... - cur.<a href="#setMode">setMode</a>( TQSqlCursor::<a href="#Mode-enum">ReadOnly</a> ); // no inserts/updates/deletes allowed - - </pre> - - -<h3 class=fn>void <a name="setName"></a>TQSqlCursor::setName ( const <a href="ntqstring.html">TQString</a> & name, bool autopopulate = TRUE )<tt> [virtual]</tt> -</h3> -Sets the name of the cursor to <em>name</em>. If <em>autopopulate</em> is TRUE -(the default), the <em>name</em> must correspond to a valid table or -view name in the database. Also, note that all references to the -cursor edit buffer become invalidated when fields are -auto-populated. See the TQSqlCursor constructor documentation for -more information. - -<h3 class=fn>void <a name="setPrimaryIndex"></a>TQSqlCursor::setPrimaryIndex ( const <a href="ntqsqlindex.html">TQSqlIndex</a> & idx )<tt> [virtual]</tt> -</h3> -Sets the primary index associated with the cursor to the index <em>idx</em>. Note that this index must contain a field or set of fields -which identify a unique record within the underlying database -table or view so that <a href="#update">update</a>() and <a href="#del">del</a>() will execute as expected. -<p> <p>See also <a href="#update">update</a>() and <a href="#del">del</a>(). - -<h3 class=fn>void <a name="setSort"></a>TQSqlCursor::setSort ( const <a href="ntqsqlindex.html">TQSqlIndex</a> & sort )<tt> [virtual]</tt> -</h3> -Sets the current sort to <em>sort</em>. Note that no new records are -selected. To select new records, use <a href="#select">select</a>(). The <em>sort</em> will -apply to any subsequent select() calls that do not explicitly -specify a sort. - -<h3 class=fn>void <a name="setTrimmed"></a>TQSqlCursor::setTrimmed ( const <a href="ntqstring.html">TQString</a> & name, bool trim )<tt> [virtual]</tt> -</h3> -Sets field <em>name</em>'s trimmed status to <em>trim</em>. If the field <em>name</em> does not exist, nothing happens. -<p> When a trimmed field of type string or cstring is read from the -database any trailing (right-most) spaces are removed. -<p> <p>See also <a href="#isTrimmed">isTrimmed</a>() and <a href="ntqvariant.html">TQVariant</a>. - -<h3 class=fn><a href="ntqsqlindex.html">TQSqlIndex</a> <a name="sort"></a>TQSqlCursor::sort () const -</h3> -Returns the current sort, or an empty index if there is no current -sort. - -<h3 class=fn><a href="ntqstring.html">TQString</a> <a name="toString"></a>TQSqlCursor::toString ( <a href="ntqsqlrecord.html">TQSqlRecord</a> * rec, const <a href="ntqstring.html">TQString</a> & prefix, const <a href="ntqstring.html">TQString</a> & fieldSep, const <a href="ntqstring.html">TQString</a> & sep ) const<tt> [virtual protected]</tt> -</h3> -Returns a formatted string composed of all the fields in <em>rec</em>. -Each field is composed of the <em>prefix</em> (e.g. table or view name), -".", the field name, the <em>fieldSep</em> and the field value. If the -<em>prefix</em> is empty then each field will begin with the field name. -The fields are then joined together separated by <em>sep</em>. Fields -where <a href="ntqsqlrecord.html#isGenerated">isGenerated</a>() returns FALSE are not included. This function -is useful for generating SQL statements. - -<h3 class=fn><a href="ntqstring.html">TQString</a> <a name="toString-3"></a>TQSqlCursor::toString ( const <a href="ntqstring.html">TQString</a> & prefix, <a href="ntqsqlfield.html">TQSqlField</a> * field, const <a href="ntqstring.html">TQString</a> & fieldSep ) const<tt> [virtual protected]</tt> -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Returns a formatted string composed of the <em>prefix</em> (e.g. table -or view name), ".", the <em>field</em> name, the <em>fieldSep</em> and the -field value. If the <em>prefix</em> is empty then the string will begin -with the <em>field</em> name. This function is useful for generating SQL -statements. - -<h3 class=fn><a href="ntqstring.html">TQString</a> <a name="toString-4"></a>TQSqlCursor::toString ( const <a href="ntqsqlindex.html">TQSqlIndex</a> & i, <a href="ntqsqlrecord.html">TQSqlRecord</a> * rec, const <a href="ntqstring.html">TQString</a> & prefix, const <a href="ntqstring.html">TQString</a> & fieldSep, const <a href="ntqstring.html">TQString</a> & sep ) const<tt> [virtual protected]</tt> -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Returns a formatted string composed of all the fields in the index -<em>i</em>. Each field is composed of the <em>prefix</em> (e.g. table or view -name), ".", the field name, the <em>fieldSep</em> and the field value. -If the <em>prefix</em> is empty then each field will begin with the field -name. The field values are taken from <em>rec</em>. The fields are then -joined together separated by <em>sep</em>. Fields where <a href="ntqsqlrecord.html#isGenerated">isGenerated</a>() -returns FALSE are ignored. This function is useful for generating -SQL statements. - -<h3 class=fn>int <a name="update"></a>TQSqlCursor::update ( bool invalidate = TRUE )<tt> [virtual]</tt> -</h3> -Updates the database with the current contents of the edit buffer. -Returns the number of records which were updated. -For error information, use <a href="ntqsqlquery.html#lastError">lastError</a>(). -<p> Only records which meet the filter criteria specified by the -cursor's primary index are updated. If the cursor does not contain -a primary index, no update is performed and 0 is returned. -<p> If <em>invalidate</em> is TRUE (the default), the current cursor can no -longer be navigated. A new <a href="#select">select</a>() call must be made before you -can move to a valid record. For example: -<p> - -<pre> TQSqlCursor cur( "prices" ); - <a name="x2200"></a> cur.<a href="#select">select</a>( "id=202" ); - if ( cur.<a href="ntqsqlquery.html#next">next</a>() ) { - <a name="x2199"></a> <a href="ntqsqlrecord.html">TQSqlRecord</a> *buffer = cur.<a href="#primeUpdate">primeUpdate</a>(); - <a name="x2204"></a> double price = buffer-><a href="ntqsqlrecord.html#value">value</a>( "price" ).toDouble(); - double newprice = price * 1.05; - <a name="x2203"></a> buffer-><a href="ntqsqlrecord.html#setValue">setValue</a>( "price", newprice ); - <a name="x2201"></a> cur.<a href="#update">update</a>(); - } -</pre> -<p> In the above example, a cursor is created on the 'prices' table -and is positioned on the record to be updated. Then a pointer to -the cursor's edit buffer is acquired using <a href="#primeUpdate">primeUpdate</a>(). A new -value is calculated and placed into the edit buffer with the -<a href="ntqsqlrecord.html#setValue">setValue</a>() call. Finally, an <a href="#update">update</a>() call is made on the cursor -which uses the tables's primary index to update the record in the -database with the contents of the cursor's edit buffer. Remember: -all edit operations (<a href="#insert">insert</a>(), update() and delete()) operate on -the contents of the cursor edit buffer and not on the contents of -the cursor itself. -<p> Note that if the primary index does not uniquely distinguish -records the database may be changed into an inconsistent state. -<p> <p>See also <a href="#setMode">setMode</a>() and <a href="ntqsqlquery.html#lastError">lastError</a>(). - -<p>Example: <a href="sql.html#x2201">sql/overview/update/main.cpp</a>. -<h3 class=fn>int <a name="update-2"></a>TQSqlCursor::update ( const <a href="ntqstring.html">TQString</a> & filter, bool invalidate = TRUE )<tt> [virtual protected]</tt> -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Updates the database with the current contents of the cursor edit -buffer using the specified <em>filter</em>. Returns the number of -records which were updated. -For error information, use <a href="ntqsqlquery.html#lastError">lastError</a>(). -<p> Only records which meet the filter criteria are updated, otherwise -all records in the table are updated. -<p> If <em>invalidate</em> is TRUE (the default), the cursor can no longer -be navigated. A new <a href="#select">select</a>() call must be made before you can move -to a valid record. -<p> <p>See also <a href="#primeUpdate">primeUpdate</a>(), <a href="#setMode">setMode</a>(), and <a href="ntqsqlquery.html#lastError">lastError</a>(). - -<!-- eof --> -<hr><p> -This file is part of the <a href="index.html">TQt toolkit</a>. -Copyright © 1995-2007 -<a href="http://www.trolltech.com/">Trolltech</a>. 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