Class: QgsFieldConstraints¶

class qgis.core.QgsFieldConstraints¶

Bases: sip.wrapper

Constructor for QgsFieldConstraints.

QgsFieldConstraints(QgsFieldConstraints)

Stores information about constraints which may be present on a field.

New in version 3.0: Enums

Methods

`constraintDescription`	Returns the descriptive name for the constraint expression.
`constraintExpression`	Returns the constraint expression for the field, if set.
`constraintOrigin`	Returns the origin of a field constraint, or ConstraintOriginNotSet if the constraint is not present on this field.
`constraintStrength`	Returns the strength of a field constraint, or ConstraintStrengthNotSet if the constraint is not present on this field.
`constraints`	Returns any constraints which are present for the field.
`removeConstraint`	Removes a constraint from the field.
`setConstraint`	Sets a constraint on the field.
`setConstraintExpression`	Set the constraint expression for the field.
`setConstraintStrength`	Sets the strength of a constraint.

Signals

Attributes

`ConstraintExpression`
`ConstraintNotNull`
`ConstraintOriginLayer`
`ConstraintOriginNotSet`
`ConstraintOriginProvider`
`ConstraintStrengthHard`
`ConstraintStrengthNotSet`
`ConstraintStrengthSoft`
`ConstraintUnique`
`staticMetaObject`

class Constraint¶: Bases: int

ConstraintExpression = 4¶

ConstraintNotNull = 1¶

class ConstraintOrigin¶: Bases: int

ConstraintOriginLayer = 2¶

ConstraintOriginNotSet = 0¶

ConstraintOriginProvider = 1¶

class ConstraintStrength¶: Bases: int

ConstraintStrengthHard = 1¶

ConstraintStrengthNotSet = 0¶

ConstraintStrengthSoft = 2¶

ConstraintUnique = 2¶

class Constraints¶

Bases: sip.wrapper

QgsFieldConstraints.Constraints(Union[QgsFieldConstraints.Constraints, QgsFieldConstraints.Constraint]) QgsFieldConstraints.Constraints(QgsFieldConstraints.Constraints)

constraintDescription(self) → str¶: Returns the descriptive name for the constraint expression.

See also

constraints()

See also

constraintExpression()

See also

setConstraintExpression()

constraintExpression(self) → str¶: Returns the constraint expression for the field, if set.

See also

constraints()

See also

constraintDescription()

See also

setConstraintExpression()

constraintOrigin(self, constraint: QgsFieldConstraints.Constraint) → QgsFieldConstraints.ConstraintOrigin¶: Returns the origin of a field constraint, or ConstraintOriginNotSet if the constraint is not present on this field.

See also

constraints()

constraintStrength(self, constraint: QgsFieldConstraints.Constraint) → QgsFieldConstraints.ConstraintStrength¶: Returns the strength of a field constraint, or ConstraintStrengthNotSet if the constraint is not present on this field.

See also

constraints()

See also

setConstraintStrength()

constraints(self) → QgsFieldConstraints.Constraints¶: Returns any constraints which are present for the field.

See also

setConstraint()

See also

constraintOrigin()

removeConstraint(self, constraint: QgsFieldConstraints.Constraint)¶: Removes a constraint from the field.

See also

setConstraint()

See also

constraints()

setConstraint(self, constraint: QgsFieldConstraints.Constraint, origin: QgsFieldConstraints.ConstraintOrigin = QgsFieldConstraints.ConstraintOriginLayer)¶: Sets a constraint on the field.

See also

constraints()

See also

removeConstraint()

setConstraintExpression(self, expression: str, description: str = '')¶: Set the constraint expression for the field. An optional descriptive name for the constraint can also be set. Setting an empty expression will clear any existing expression constraint.

See also

constraintExpression()

See also

constraintDescription()

See also

constraints()

setConstraintStrength(self, constraint: QgsFieldConstraints.Constraint, strength: QgsFieldConstraints.ConstraintStrength)¶: Sets the strength of a constraint. Constraints default to ConstraintStrengthHard unless explicitly changed.

See also

constraintStrength()

staticMetaObject = <PyQt5.QtCore.QMetaObject object>¶