Knowledge - 'SQL CHECK Constraint'

SQL CHECK Constraint

SQL 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 tab...See more

le it can limit the values in certain columns based on values in other columns in the row. ________________________________________ SQL CHECK on CREATE TABLE The following SQL creates a CHECK constraint on the "Age" column when the "Persons" table is created. The CHECK constraint ensures that you can not have any person below 18 years: MySQL: CREATE TABLE Persons ( ID int NOT NULL, LastName varchar(255) NOT NULL, FirstName varchar(255), Age int, CHECK (Age>=18) ); SQL Server / Oracle / MS Access:

Added: 4 years ago