QSqlRecord Class
The QSqlRecord class encapsulates a database record. More...
| Header: | #include <QSqlRecord> |
| CMake: | find_package(Qt6 REQUIRED COMPONENTS Sql)target_link_libraries(mytarget PRIVATE Qt6::Sql) |
| qmake: | QT += sql |
| Inherited By: |
- List of all members, including inherited members
- QSqlRecord is part of Database Classes and Implicitly Shared Classes.
Public Functions
| QSqlRecord() | |
| QSqlRecord(const QSqlRecord &other) | |
(since 6.6) | 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) |
(since 6.6) void | swap(QSqlRecord &other) |
| QVariant | value(int index) const |
| QVariant | value(QAnyStringView name) const |
| bool | operator!=(const QSqlRecord &other) const |
(since 6.6) QSqlRecord & | operator=(QSqlRecord &&other) |
| QSqlRecord & | operator=(const QSqlRecord &other) |
| bool | operator==(const QSqlRecord &other) const |
Detailed Description
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(). Use 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() or 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().
See also QSqlField and QSqlQuery::record().
Member Function Documentation
QSqlRecord::QSqlRecord()
Constructs an empty record.
See also isEmpty(), append(), and insert().
QSqlRecord::QSqlRecord(const QSqlRecord &other)
Constructs a copy of other.
QSqlRecord is implicitly shared. This means you can make copies of a record in constant time.
[noexcept, since 6.6] QSqlRecord::QSqlRecord(QSqlRecord &&other)
Move-constructs a new QSqlRecord from other.
Note: 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.
This function was introduced in Qt 6.6.
[noexcept] QSqlRecord::~QSqlRecord()
Destroys the object and frees any allocated resources.
void QSqlRecord::append(const QSqlField &field)
Append a copy of field field to the end of the record.
See also insert(), replace(), and remove().
void QSqlRecord::clear()
Removes all the record's fields.
See also clearValues() and isEmpty().
void QSqlRecord::clearValues()
Clears the value of all fields in the record and sets each field to null.
See also setValue().
bool QSqlRecord::contains(QAnyStringView name) const
Returns true if there is a field in the record called name; otherwise returns false.
Note: In Qt versions prior to 6.8, this function took QString, not QAnyStringView.
int QSqlRecord::count() const
Returns the number of fields in the record.
See also isEmpty().
QSqlField QSqlRecord::field(int index) const
Returns the field at position index. If the index is out of range, function returns a default-constructed value.
QSqlField QSqlRecord::field(QAnyStringView name) const
This is an overloaded function.
Returns the field called name. If the field called name is not found, function returns a default-constructed value.
Note: In Qt versions prior to 6.8, this function took QString, not QAnyStringView.
QString QSqlRecord::fieldName(int index) const
Returns the name of the field at position index. If the field does not exist, an empty string is returned.
See also indexOf().
int QSqlRecord::indexOf(QAnyStringView name) const
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.
Note: In Qt versions prior to 6.8, this function took QString, not QAnyStringView.
See also fieldName().
void QSqlRecord::insert(int pos, const QSqlField &field)
Inserts the field field at position pos in the record.
See also append(), replace(), and remove().
bool QSqlRecord::isEmpty() const
Returns true if there are no fields in the record; otherwise returns false.
See also append(), insert(), and clear().
bool QSqlRecord::isGenerated(int index) const
Returns true if the record has a field at position index and this field is to be generated (the default); otherwise returns false.
See also setGenerated().
bool QSqlRecord::isGenerated(QAnyStringView name) const
This is an overloaded function.
Returns true if the record has a field called name and this field is to be generated (the default); otherwise returns false.
Note: In Qt versions prior to 6.8, this function took QString, not QAnyStringView.
See also setGenerated().
bool QSqlRecord::isNull(int index) const
Returns true if the field index is null or if there is no field at position index; otherwise returns false.
See also setNull().
bool QSqlRecord::isNull(QAnyStringView name) const
This is an overloaded function.
Returns true if the field called name is null or if there is no field called name; otherwise returns false.
Note: In Qt versions prior to 6.8, this function took QString, not QAnyStringView.
See also setNull().
QSqlRecord QSqlRecord::keyValues(const QSqlRecord &keyFields) const
Returns a record containing the fields represented in keyFields set to values that match by field name.
void QSqlRecord::remove(int pos)
Removes the field at position pos. If pos is out of range, nothing happens.
See also append(), insert(), and replace().
void QSqlRecord::replace(int pos, const QSqlField &field)
Replaces the field at position pos with the given field. If pos is out of range, nothing happens.
See also append(), insert(), and remove().
void QSqlRecord::setGenerated(QAnyStringView name, bool generated)
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 for example.
Note: In Qt versions prior to 6.8, this function took QString, not QAnyStringView.
See also isGenerated().
void QSqlRecord::setGenerated(int index, bool generated)
Sets the generated flag for the field index to generated.
See also isGenerated().
void QSqlRecord::setNull(int index)
Sets the value of field index to null. If the field does not exist, nothing happens.
See also isNull() and setValue().
void QSqlRecord::setNull(QAnyStringView name)
This is an overloaded function.
Sets the value of the field called name to null. If the field does not exist, nothing happens.
Note: In Qt versions prior to 6.8, this function took QString, not QAnyStringView.
void QSqlRecord::setValue(int index, const QVariant &val)
Sets the value of the field at position index to val. If the field does not exist, nothing happens.
See also value() and setNull().
void QSqlRecord::setValue(QAnyStringView name, const QVariant &val)
This is an overloaded function.
Sets the value of the field called name to val. If the field does not exist, nothing happens.
Note: In Qt versions prior to 6.8, this function took QString, not QAnyStringView.
See also setNull().
[noexcept, since 6.6] void QSqlRecord::swap(QSqlRecord &other)
Swaps SQL record other with this SQL record. This operation is very fast and never fails.
This function was introduced in Qt 6.6.
QVariant QSqlRecord::value(int index) const
Returns the value of the field located at position index in the record. If index is out of bounds, an invalid QVariant is returned.
See also setValue(), fieldName(), and isNull().
QVariant QSqlRecord::value(QAnyStringView name) const
This is an overloaded function.
Returns the value of the field called name in the record. If field name does not exist an invalid variant is returned.
Note: In Qt versions prior to 6.8, this function took QString, not QAnyStringView.
See also indexOf() and isNull().
bool QSqlRecord::operator!=(const QSqlRecord &other) const
Returns true if this object is not identical to other; otherwise returns false.
See also operator==().
[noexcept, since 6.6] QSqlRecord &QSqlRecord::operator=(QSqlRecord &&other)
Move-assigns other to this QSqlRecord instance.
Note: 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.
This function was introduced in Qt 6.6.
QSqlRecord &QSqlRecord::operator=(const QSqlRecord &other)
Sets the record equal to other.
QSqlRecord is implicitly shared. This means you can make copies of a record in constant time.
bool QSqlRecord::operator==(const QSqlRecord &other) const
Returns true if this object is identical to other (i.e., has the same fields in the same order); otherwise returns false.
See also operator!=().