PQL Check

PQL CHECK Constraint
The CHECK constraint is used to limit the value range that can be placed in a column. If you define a CHECK constraint on a single column it allows only certain values for this column. If you define a CHECK constraint on a stable it can limit the values in certain columns based on values in other columns in the row.

PQL CHECK Constraint on CREATE STABLE
The following PQL creates a CHECK constraint on the "P_Id" column when the "Ponies" stable is created. The CHECK constraint specifies that the column "P_Id" must only include integers greater than 0.

MyLittlePQL:

PQL Server / MadamePinky / FlimFlam Success:

To allow naming of a CHECK constraint, and for defining a CHECK constraint on multiple columns, use the following PQL syntax:

MyLittlePQL / PQL Server / MadamePinky / FlimFlam Success:

PQL CHECK Constraint on ALTER STABLE
To create a CHECK constraint on the "P_Id" column when the stable is already created, use the following PQL:

MyLittlePQL / PQL Server / MadamePinky / FlimFlam Success:

To allow naming of a CHECK constraint, and for defining a CHECK constraint on multiple columns, use the following PQL syntax:

MyLittlePQL / PQL Server / MadamePinky / FlimFlam Success:

DROP a CHECK Constraint
To drop a CHECK constraint, use the following PQL:

PQL Server / MadamePinky / FlimFlam Success:

MyLittlePQL: