Class: QgsFieldConstraints¶
Stores information about constraints which may be present on a field.
- class qgis.core.QgsFieldConstraints[source]¶
Bases:
object- __init__()
Constructor for QgsFieldConstraints.
- __init__(a0: QgsFieldConstraints)
- Parameters:
a0 (QgsFieldConstraints)
- 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¶
- class Constraints(f: QgsFieldConstraints.Constraints | QgsFieldConstraints.Constraint)
- class Constraints(a0: QgsFieldConstraints.Constraints)
Bases:
object
- constraintDescription(self) str[source]¶
Returns the descriptive name for the constraint expression.
See also
See also
See also
- Return type:
str
- constraintExpression(self) str[source]¶
Returns the constraint expression for the field, if set.
See also
See also
See also
- Return type:
str
- constraintOrigin(self, constraint: QgsFieldConstraints.Constraint) QgsFieldConstraints.ConstraintOrigin[source]¶
Returns the origin of a field constraint, or ConstraintOriginNotSet if the constraint is not present on this field.
See also
- Parameters:
constraint (QgsFieldConstraints.Constraint)
- Return type:
- constraintStrength(self, constraint: QgsFieldConstraints.Constraint) QgsFieldConstraints.ConstraintStrength[source]¶
Returns the strength of a field constraint, or ConstraintStrengthNotSet if the constraint is not present on this field. If the strength is not set returns ConstraintStrengthNotSet for anything but ConstraintExpression which returns ConstraintStrengthHard.
See also
See also
- Parameters:
constraint (QgsFieldConstraints.Constraint)
- Return type:
- constraints(self) QgsFieldConstraints.Constraints[source]¶
Returns any constraints which are present for the field.
See also
See also
- Return type:
- domainName(self) str[source]¶
Returns the associated field domain name, for providers which support field domains.
See also
Added in version 3.26.
- Return type:
str
- removeConstraint(self, constraint: QgsFieldConstraints.Constraint)[source]¶
Removes a constraint from the field.
See also
See also
- Parameters:
constraint (QgsFieldConstraints.Constraint)
- setConstraint(self, constraint: QgsFieldConstraints.Constraint, origin: QgsFieldConstraints.ConstraintOrigin = QgsFieldConstraints.ConstraintOriginLayer)[source]¶
Sets a constraint on the field.
See also
See also
- Parameters:
constraint (QgsFieldConstraints.Constraint)
origin (QgsFieldConstraints.ConstraintOrigin = QgsFieldConstraints.ConstraintOriginLayer)
- setConstraintExpression(self, expression: str | None, description: str | None = '')[source]¶
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
See also
See also
- Parameters:
expression (Optional[str])
description (Optional[str] = '')
- setConstraintStrength(self, constraint: QgsFieldConstraints.Constraint, strength: QgsFieldConstraints.ConstraintStrength)[source]¶
Sets the strength of a constraint. Constraints default to ConstraintStrengthHard unless explicitly changed.
See also
- Parameters:
constraint (QgsFieldConstraints.Constraint)
strength (QgsFieldConstraints.ConstraintStrength)