sql check if constraint code example
Example 1: check constraint in sql
CREATE TABLE Persons (
ID int NOT NULL,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Age int,
City varchar(255),
CONSTRAINT CHK_Person CHECK (Age>=18 AND City='Sandnes')
);
Example 2: check constraint in sql
#Add Check
ALTER TABLE Persons
ADD CONSTRAINT CHK_PersonAge CHECK (Age>=18 AND City='Sandnes');
#Drop Check
ALTER TABLE Persons
DROP CHECK CHK_PersonAge;