Home Man
Today's Posts

Linux & Unix Commands - Search Man Pages

RedHat 9 (Linux i386) - man page for qsqlfield (redhat section 3qt)

QSqlField(3qt)									   QSqlField(3qt)

       QSqlField - Manipulates the fields in SQL database tables and views

       #include <qsqlfield.h>

   Public Members
       QSqlField ( const QString & fieldName = QString::null, QVariant::Type type =
	   QVariant::Invalid )
       QSqlField ( const QSqlField & other )
       QSqlField & operator= ( const QSqlField & other )
       bool operator== ( const QSqlField & other ) const
       virtual ~QSqlField ()
       virtual void setValue ( const QVariant & value )
       virtual QVariant value () const
       virtual void setName ( const QString & name )
       QString name () const
       virtual void setNull ()
       bool isNull () const
       virtual void setReadOnly ( bool readOnly )
       bool isReadOnly () const
       void clear ( bool nullify = TRUE )
       QVariant::Type type () const

       The QSqlField class manipulates the fields in SQL database tables and views.

       QSqlField represents the characteristics of a single column in a database table or view,
       such as the data type and column name. A field also contains the value of the database
       column, which can be viewed or changed.

       Field data values are stored as QVariants. Using an incompatible type is not permitted.
       For example:

	   QSqlField f( "myfield", QVariant::Int );
	   f.setValue( QPixmap() );  // will not work

       However, the field will attempt to cast certain data types to the field data type where

	   QSqlField f( "myfield", QVariant::Int );
	   f.setValue( QString("123") ); // casts QString to int

       QSqlField objects are rarely created explicitly in application code. They are usually
       accessed indirectly through QSqlRecord or QSqlCursor which already contain a list of
       fields. For example:

	   QSqlCursor cur( "Employee" );	// create cursor using the 'Employee' table
	   QSqlField* f = cur.field( "name" );	// use the 'name' field
	   f->setValue( "Dave" );		// set field value

       In practice we rarely need to extract a pointer to a field at all. The previous example
       would normally be written:

	   QSqlCursor cur( "Employee" );
	   cur.setValue( "name", "Dave" );

       See also Database Classes.

QSqlField::QSqlField ( const QString & fieldName = QString::null, QVariant::Type type =
       QVariant::Invalid )
       Constructs an empty field called fieldName of type type.

QSqlField::QSqlField ( const QSqlField & other )
       Constructs a copy of other.

QSqlField::~QSqlField () [virtual]
       Destroys the object and frees any allocated resources.

void QSqlField::clear ( bool nullify = TRUE )
       Clears the value of the field. If the field is read-only, nothing happens. If nullify is
       TRUE (the default), the field is set to NULL.

bool QSqlField::isNull () const
       Returns TRUE if the field is currently NULL; otherwise returns FALSE.

bool QSqlField::isReadOnly () const
       Returns TRUE if the field's value is read only; otherwise returns FALSE.

QString QSqlField::name () const
       Returns the name of the field.

       Example: sql/overview/table4/main.cpp.

QSqlField &; QSqlField::operator= ( const QSqlField & other )
       Sets the field equal to other.

bool QSqlField::operator== ( const QSqlField & other ) const
       Returns TRUE if the field is equal to other; otherwise returns FALSE. Fields are
       considered equal when the following field properties are the same:





void QSqlField::setName ( const QString & name ) [virtual]
       Sets the name of the field to name.

void QSqlField::setNull () [virtual]
       Sets the field to NULL and clears the value using clear(). If the field is read-only,
       nothing happens.

       See also isReadOnly() and clear().

void QSqlField::setReadOnly ( bool readOnly ) [virtual]
       Sets the read only flag of the field's value to readOnly.

       See also setValue().

void QSqlField::setValue ( const QVariant & value ) [virtual]
       Sets the value of the field to value. If the field is read-only (isReadOnly() returns
       TRUE), nothing happens. If the data type of value differs from the field's current data
       type, an attempt is made to cast it to the proper type. This preserves the data type of
       the field in the case of assignment, e.g. a QString to an integer data type. For example:

	   QSqlCursor cur( "Employee" );		 // 'Employee' table
	   QSqlField* f = cur.field( "student_count" );  // an integer field
	   f->setValue( myLineEdit->text() );		 // cast the line edit text to an integer

       See also isReadOnly().

QVariant::Type QSqlField::type () const
       Returns the field's type.

QVariant QSqlField::value () const [virtual]
       Returns the value of the field as a QVariant.

       Example: sql/overview/table4/main.cpp.

       http://doc.trolltech.com/qsqlfield.html http://www.trolltech.com/faq/tech.html

       Copyright 1992-2001 Trolltech AS, http://www.trolltech.com.  See the license file included
       in the distribution for a complete license statement.

       Generated automatically from the source code.

       If you find a bug in Qt, please report it as described in
       http://doc.trolltech.com/bughowto.html.	Good bug reports help us to help you. Thank you.

       The definitive Qt documentation is provided in HTML format; it is located at
       $QTDIR/doc/html and can be read using Qt Assistant or with a web browser. This man page is
       provided as a convenience for those users who prefer man pages, although this format is
       not officially supported by Trolltech.

       If you find errors in this manual page, please report them to qt-bugs@trolltech.com.
       Please include the name of the manual page (qsqlfield.3qt) and the Qt version (3.1.1).

Trolltech AS				 9 December 2002			   QSqlField(3qt)

All times are GMT -4. The time now is 08:32 AM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
Show Password