From d796c9dd933ab96ec83b9a634feedd5d32e1ba3f Mon Sep 17 00:00:00 2001 From: Timothy Pearson Date: Tue, 8 Nov 2011 12:31:36 -0600 Subject: Test conversion to TQt3 from Qt3 8c6fc1f8e35fd264dd01c582ca5e7549b32ab731 --- doc/html/qsqlfield.html | 216 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 216 insertions(+) create mode 100644 doc/html/qsqlfield.html (limited to 'doc/html/qsqlfield.html') diff --git a/doc/html/qsqlfield.html b/doc/html/qsqlfield.html new file mode 100644 index 000000000..fc2cdb2d5 --- /dev/null +++ b/doc/html/qsqlfield.html @@ -0,0 +1,216 @@ + + + + + +TQSqlField Class + + + + + + + +

TQSqlField Class Reference
[sql module]

+ +

The TQSqlField class manipulates the fields in SQL database tables +and views. +More... +

#include <qsqlfield.h> +

List of all member functions. +

Public Members

TQSqlField ( const TQString & fieldName = TQString::null, TQVariant::Type type = TQVariant::Invalid )
TQSqlField ( const TQSqlField & other )
TQSqlField & operator= ( const TQSqlField & other )
bool operator== ( const TQSqlField & other ) const
virtual ~TQSqlField ()
virtual void setValue ( const TQVariant & value )
virtual TQVariant value () const
virtual void setName ( const TQString & name )
TQString name () const
virtual void setNull ()
bool isNull () const
virtual void setReadOnly ( bool readOnly )
bool isReadOnly () const
void clear ( bool nullify = TRUE )
TQVariant::Type type () const

Detailed Description

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

+ +

TQSqlField 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 TQVariants. Using an incompatible +type is not permitted. For example: +

+    TQSqlField f( "myfield", TQVariant::Int );
+    f.setValue( TQPixmap() );  // will not work
+

+ +

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

+    TQSqlField f( "myfield", TQVariant::Int );
+    f.setValue( TQString("123") ); // casts TQString to int
+

+ +

TQSqlField objects are rarely created explicitly in application +code. They are usually accessed indirectly through TQSqlRecord +or TQSqlCursor which already contain a list of fields. For +example: +

+    TQSqlCursor cur( "Employee" );        // create cursor using the 'Employee' table
+    TQSqlField* 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: +

+    TQSqlCursor cur( "Employee" );
+    cur.setValue( "name", "Dave" );
+    ...
+

+ +

Member Function Documentation

TQSqlField::TQSqlField ( const TQString & fieldName = TQString::null, TQVariant::Type type = TQVariant::Invalid ) +

+Constructs an empty field called fieldName of type type. + +

TQSqlField::TQSqlField ( const TQSqlField & other ) +

+Constructs a copy of other. + +

TQSqlField::~TQSqlField () `[virtual]` +

+Destroys the object and frees any allocated resources. + +

void TQSqlField::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 TQSqlField::isNull () const +

+ +

Returns TRUE if the field is currently NULL; otherwise returns +FALSE. + +

bool TQSqlField::isReadOnly () const +

+ +

Returns TRUE if the field's value is read only; otherwise returns +FALSE. + +

TQString TQSqlField::name () const +

+ +

Returns the name of the field. + +

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

TQSqlField & TQSqlField::operator= ( const TQSqlField & other ) +

+Sets the field equal to other. + +

bool TQSqlField::operator== ( const TQSqlField & 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: +

name() +
isNull() +
value() +
isReadOnly() +

void TQSqlField::setName ( const TQString & name ) `[virtual]` +

+ +

Sets the name of the field to name. + +

void TQSqlField::setNull () `[virtual]` +

+ +

Sets the field to NULL and clears the value using clear(). If the +field is read-only, nothing happens. +

void TQSqlField::setReadOnly ( bool readOnly ) `[virtual]` +

+ +

Sets the read only flag of the field's value to readOnly. +

void TQSqlField::setValue ( const TQVariant & 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 TQString to an +integer data type. For example: +

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

+ +

TQVariant::Type TQSqlField::type () const +

+ +

Returns the field's type as stored in the database. +Note that the actual value might have a different type, +Numerical values that are too large to store in a long +int or double are usually stored as strings to prevent +precision loss. + +

TQVariant TQSqlField::value () const `[virtual]` +

+ +

Returns the value of the field as a TQVariant. + +

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

+ +

Trademarks +

TQt 3.3.8

+ -- cgit v1.2.1

TQSqlField Class Reference[sql module]