mysql CHECK constraints

[ Chess] general one army

n.<US> check; stop, suppress; check, check

Third person singular: checks Plural: checks Present participle: check Past tense: checked past Participle: checked

mysql CHECK constraints syntax

Function: CHECK constraints are used to limit the range of values ​​in the column.

Note: If a CHECK constraint is defined on a single column, only specific values ​​are allowed for that column. If a CHECK constraint is defined on a table, the constraint limits values ​​in a specific column.

mysql CHECK constraints example

//在 "Persons" 表创建时为 "Id_P" 列创建 CHECK 约束。CHECK 约束规定 "Id_P" 列必须只包含大于 0 的整数。
CREATE TABLE Persons(Id_P int NOT NULL,LastName varchar(255) NOT NULL,FirstName varchar(255),Address varchar(255),City varchar(255),CHECK (Id_P>0));