QSqlRecord 类封装数据库记录。 更多...
| 头： |
#include <QSqlRecord>
|
| CMake: |
find_package(Qt6 REQUIRED COMPONENTS Sql)
target_link_libraries(mytarget PRIVATE Qt6::Sql)
|
| qmake: |
QT += sql
|
| 继承者： |
| QSqlRecord () | |
| QSqlRecord (const QSqlRecord & other ) | |
(从 6.6 起)
|
QSqlRecord (QSqlRecord && other ) |
| ~QSqlRecord () | |
| void | append (const QSqlField & field ) |
| void | clear () |
| void | clearValues () |
| bool | contains (QAnyStringView name ) const |
| int | count () const |
| QSqlField | field (int index ) const |
| QSqlField | field (QAnyStringView name ) const |
| QString | fieldName (int index ) const |
| int | indexOf (QAnyStringView name ) const |
| void | insert (int pos , const QSqlField & field ) |
| bool | isEmpty () const |
| bool | isGenerated (int index ) const |
| bool | isGenerated (QAnyStringView name ) const |
| bool | isNull (int index ) const |
| bool | isNull (QAnyStringView name ) const |
| QSqlRecord | keyValues (const QSqlRecord & keyFields ) const |
| void | remove (int pos ) |
| void | replace (int pos , const QSqlField & field ) |
| void | setGenerated (QAnyStringView name , bool generated ) |
| void | setGenerated (int index , bool generated ) |
| void | setNull (int index ) |
| void | setNull (QAnyStringView name ) |
| void | setValue (int index , const QVariant & val ) |
| void | setValue (QAnyStringView name , const QVariant & val ) |
(从 6.6 起)
void
|
swap (QSqlRecord & other ) |
| QVariant | value (int index ) const |
| QVariant | value (QAnyStringView name ) const |
| bool | operator!= (const QSqlRecord & other ) const |
(从 6.6 起)
QSqlRecord &
|
operator= (QSqlRecord && other ) |
| QSqlRecord & | operator= (const QSqlRecord & other ) |
| bool | operator== (const QSqlRecord & other ) const |
The QSqlRecord class encapsulates the functionality and characteristics of a database record (usually a row in a table or view within the database). QSqlRecord supports adding and removing fields as well as setting and retrieving field values.
The values of a record's fields can be set by name or position with setValue (); if you want to set a field to null use setNull (). To find the position of a field by name use indexOf (), and to find the name of a field at a particular position use fieldName ()。使用 field () to retrieve a QSqlField object for a given field. Use contains () to see if the record contains a particular field name.
When queries are generated to be executed on the database only those fields for which isGenerated () is true are included in the generated SQL.
A record can have fields added with append () 或 insert (), replaced with replace (), and removed with remove (). All the fields can be removed with clear (). The number of fields is given by count (); all their values can be cleared (to null) using clearValues ().
另请参阅 QSqlField and QSqlQuery::record ().
Constructs an empty record.
另请参阅 isEmpty (), append ()，和 insert ().
构造副本为 other .
QSqlRecord is 隐式共享 . This means you can make copies of a record in 常量时间 .
[noexcept, since 6.6]
QSqlRecord::
QSqlRecord
(
QSqlRecord
&&
other
)
Move-constructs a new QSqlRecord from other .
注意： The moved-from object other is placed in a partially-formed state, in which the only valid operations are destruction and assignment of a new value.
该函数在 Qt 6.6 引入。
[noexcept]
QSqlRecord::
~QSqlRecord
()
销毁对象并释放任何分配资源。
Append a copy of field field to the end of the record.
另请参阅 insert (), replace ()，和 remove ().
Removes all the record's fields.
另请参阅 clearValues () 和 isEmpty ().
Clears the value of all fields in the record and sets each field to null.
另请参阅 setValue ().
返回
true
if there is a field in the record called
name
；否则返回
false
.
注意： In Qt versions prior to 6.8, this function took QString , not QAnyStringView .
Returns the number of fields in the record.
另请参阅 isEmpty ().
Returns the field at position index 。若 index is out of range, function returns a 默认构造值 .
这是重载函数。
Returns the field called name . If the field called name is not found, function returns a 默认构造值 .
注意： In Qt versions prior to 6.8, this function took QString , not QAnyStringView .
Returns the name of the field at position index . If the field does not exist, an empty string is returned.
另请参阅 indexOf ().
Returns the position of the field called name within the record, or -1 if it cannot be found. Field names are not case-sensitive. If more than one field matches, the first one is returned.
注意： In Qt versions prior to 6.8, this function took QString , not QAnyStringView .
另请参阅 fieldName ().
Inserts the field field 在位置 pos in the record.
另请参阅 append (), replace ()，和 remove ().
返回
true
if there are no fields in the record; otherwise returns
false
.
另请参阅 append (), insert ()，和 clear ().
返回
true
if the record has a field at position
index
and this field is to be generated (the default); otherwise returns
false
.
另请参阅 setGenerated ().
这是重载函数。
返回
true
if the record has a field called
name
and this field is to be generated (the default); otherwise returns
false
.
注意： In Qt versions prior to 6.8, this function took QString , not QAnyStringView .
另请参阅 setGenerated ().
返回
true
if the field
index
is null or if there is no field at position
index
；否则返回
false
.
另请参阅 setNull ().
这是重载函数。
返回
true
if the field called
name
is null or if there is no field called
name
；否则返回
false
.
注意： In Qt versions prior to 6.8, this function took QString , not QAnyStringView .
另请参阅 setNull ().
Returns a record containing the fields represented in keyFields set to values that match by field name.
Removes the field at position pos 。若 pos is out of range, nothing happens.
另请参阅 append (), insert ()，和 replace ().
Replaces the field at position pos 采用给定 field 。若 pos is out of range, nothing happens.
另请参阅 append (), insert ()，和 remove ().
Sets the generated flag for the field called name to generated . If the field does not exist, nothing happens. Only fields that have generated set to true are included in the SQL that is generated by QSqlQueryModel 例如。
注意： In Qt versions prior to 6.8, this function took QString , not QAnyStringView .
另请参阅 isGenerated ().
Sets the generated flag for the field index to generated .
另请参阅 isGenerated ().
Sets the value of field index to null. If the field does not exist, nothing happens.
这是重载函数。
Sets the value of the field called name to null. If the field does not exist, nothing happens.
注意： In Qt versions prior to 6.8, this function took QString , not QAnyStringView .
Sets the value of the field at position index to val . If the field does not exist, nothing happens.
这是重载函数。
Sets the value of the field called name to val . If the field does not exist, nothing happens.
注意： In Qt versions prior to 6.8, this function took QString , not QAnyStringView .
另请参阅 setNull ().
[noexcept, since 6.6]
void
QSqlRecord::
swap
(
QSqlRecord
&
other
)
Swaps this SQL record with other 。此操作非常快且从不失败。
该函数在 Qt 6.6 引入。
Returns the value of the field located at position index in the record. If index is out of bounds, an invalid QVariant 被返回。
另请参阅 setValue (), fieldName ()，和 isNull ().
这是重载函数。
Returns the value of the field called name in the record. If field name does not exist an invalid variant is returned.
注意： In Qt versions prior to 6.8, this function took QString , not QAnyStringView .
返回
true
if this object is not identical to
other
；否则返回
false
.
另请参阅 operator== ().
[noexcept, since 6.6]
QSqlRecord
&QSqlRecord::
operator=
(
QSqlRecord
&&
other
)
移动赋值 other 到此 QSqlRecord 实例。
注意： The moved-from object other is placed in a partially-formed state, in which the only valid operations are destruction and assignment of a new value.
该函数在 Qt 6.6 引入。
Sets the record equal to other .
QSqlRecord is 隐式共享 . This means you can make copies of a record in 常量时间 .
返回
true
if this object is identical to
other
(i.e., has the same fields in the same order); otherwise returns
false
.
另请参阅 operator!= ().