Using CHECK Constraints : Check « Constraints « SQL Server / T-SQL Tutorial






  1. SQL Server / T-SQL Tutorial
  2. Constraints
  3. Check
CHECK constraint is used to define what format and values are allowed for a column.
The syntax of the CHECK constraint is as follows:

CHECK ( logical_expression )

If the logical expression of CHECK evaluates to TRUE, the row will be inserted.
If the CHECK constraint expression evaluates to FALSE, the row insert will fail.








7.5.Check
7.5.1.Using CHECK Constraints
7.5.2.Adding a CHECK Constraint to an Existing Table
7.5.3.Constraints with name
7.5.4.CHECK Clause
7.5.5.Check Constraint
7.5.6.CHECK (DATEPART(DAY, GETDATE()) < 28)
7.5.7.A check constraint uses an expression to qualify records that are acceptable for any Inserts or Updates
7.5.8.Use or to link two conditions for check constraint
7.5.9.Using a Multicolumn CHECK Constraint
7.5.10.Check for data length
7.5.11.Pattern based constraint
7.5.12.Mark nocheck for a constraint
7.5.13.A table-level check constraint that limits Banker IDs to a specific format