sql-server - 如何在 SQL Server 中要求列中的最小字符数？

Question

CREATE TABLE [dbo].[AdminTest] (
    [AdminTestId]  INT            IDENTITY (1, 1) NOT NULL,
    [Title]        NVARCHAR (100) NOT NULL,
    [CreatedBy]    INT            NOT NULL,
    [CreatedDate]  DATETIME       NOT NULL,
    [ModifiedBy]   INT            NOT NULL,
    [ModifiedDate] DATETIME       NOT NULL,
    [TestLevelId]  INT            NOT NULL,
    [TestStatusId] INT            NOT NULL,
    [ExamId]       INT            NOT NULL,
    [Text]         NVARCHAR (MAX) NULL,
    [Sequence]     INT            DEFAULT ((1)) NOT NULL,
    [Release]      NVARCHAR (50)  DEFAULT ((1)) NOT NULL,
    [Version]      ROWVERSION     NOT NULL,
    [Price]        MONEY          DEFAULT ((0)) NOT NULL,
    [ReleaseDate]  DATETIME       NULL,
    [Code]         VARCHAR (10)   DEFAULT (LEFT(newid(), (5))) NOT NULL
);

我将“代码”列设置为默认值，但如何才能使“代码”列的值至少包含 5 个字符？

Answer 1

创建检查约束:

ALTER TABLE AdminTest
    ADD CONSTRAINT CK_AdminTest_Code_Length CHECK (LEN(Code) >= 5);
GO

引用号:CHECK Constraints