NAME¶

QSqlFieldInfo - Stores meta data associated with a SQL field

SYNOPSIS¶

#include <qsqlfield.h>

DESCRIPTION¶

The QSqlFieldInfo class stores meta data associated with a SQL field.

QSqlFieldInfo objects only store meta data; field values are stored in QSqlField objects.

All values must be set in the constructor, and may be retrieved using isRequired(), type(), length(), precision(), defaultValue(), name(), isGenerated() and typeID().

See also Database Classes.

MEMBER FUNCTION DOCUMENTATION¶

QSqlFieldInfo::QSqlFieldInfo ( const QString & name = QString::null, QVariant::Type typ = QVariant::Invalid, int required = -1, int len = -1, int prec = -1, const QVariant & defValue = QVariant ( ), int typeID = 0, bool generated = TRUE, bool trim = FALSE, bool calculated = FALSE )¶

Constructs a QSqlFieldInfo with the following parameters: <center>.nf

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QSqlFieldInfo::QSqlFieldInfo ( const QSqlFieldInfo & other )¶

Constructs a copy of other.

QSqlFieldInfo::QSqlFieldInfo ( const QSqlField & other, bool generated = TRUE )¶

Creates a QSqlFieldInfo object with the type and the name of the QSqlField other. If generated is TRUE this field will be included in auto-generated SQL statments, e.g. in QSqlCursor.

QSqlFieldInfo::~QSqlFieldInfo () [virtual]¶

Destroys the object and frees any allocated resources.

QVariant QSqlFieldInfo::defaultValue () const¶

Returns the field's default value or an empty QVariant if the field has no default value or the value couldn't be determined. The default value is the value inserted in the database when it is not explicitly specified by the user.

bool QSqlFieldInfo::isCalculated () const¶

Returns TRUE if the field is calculated; otherwise returns FALSE.

See also setCalculated().

bool QSqlFieldInfo::isGenerated () const¶

Returns TRUE if the field should be included in auto-generated SQL statments, e.g. in QSqlCursor; otherwise returns FALSE.

See also setGenerated().

int QSqlFieldInfo::isRequired () const¶

Returns a value greater than 0 if the field is required (NULL values are not allowed), 0 if it isn't required (NULL values are allowed) or less than 0 if it cannot be determined whether the field is required or not.

bool QSqlFieldInfo::isTrim () const¶

Returns TRUE if trailing whitespace should be removed from character fields; otherwise returns FALSE.

See also setTrim().

int QSqlFieldInfo::length () const¶

Returns the field's length. For fields storing text the return value is the maximum number of characters the field can hold. For non-character fields some database systems return the number of bytes needed or the number of digits allowed. If the length cannot be determined -1 is returned.

QString QSqlFieldInfo::name () const¶

Returns the name of the field in the SQL table.

Examples:

QSqlFieldInfo & QSqlFieldInfo::operator= ( const QSqlFieldInfo & other )¶

Assigns other to this field info and returns a reference to it.

bool QSqlFieldInfo::operator== ( const QSqlFieldInfo & f ) const¶

Returns TRUE if this fieldinfo is equal to f; otherwise returns FALSE.

Two field infos are considered equal if all their attributes match.

int QSqlFieldInfo::precision () const¶

Returns the field's precision or -1 if the field has no precision or it cannot be determined.

void QSqlFieldInfo::setCalculated ( bool calc ) [virtual]¶

calc set to TRUE indicates that this field is a calculated field. The value of calculated fields can by modified by subclassing QSqlCursor and overriding QSqlCursor::calculateField().

See also isCalculated().

void QSqlFieldInfo::setGenerated ( bool gen ) [virtual]¶

gen set to FALSE indicates that this field should not appear in auto-generated SQL statements (for example in QSqlCursor).

See also isGenerated().

void QSqlFieldInfo::setTrim ( bool trim ) [virtual]¶

If trim is TRUE widgets should remove trailing whitespace from character fields. This does not affect the field value but only its representation inside widgets.

See also isTrim().

QSqlField QSqlFieldInfo::toField () const¶

Returns an empty QSqlField based on the information in this QSqlFieldInfo.

QVariant::Type QSqlFieldInfo::type () const¶

Returns the field's type or QVariant::Invalid if the type is unknown.

int QSqlFieldInfo::typeID () const¶

Returns the internal type identifier as returned from the database system. The return value is 0 if the type is unknown.

Warning: This information is only useful for low-level database programming and is not database independent.

SEE ALSO¶

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

COPYRIGHT¶

Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the license file included in the distribution for a complete license statement.

AUTHOR¶

Generated automatically from the source code.

BUGS¶

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 (qsqlfieldinfo.3qt) and the Qt version (3.3.8).