SQL Server 表增加字段案例语句

IF NOT EXISTS ( 
    SELECT 1 FROM sys.sysobjects (NOLOCK) so
    INNER JOIN sys.syscolumns (NOLOCK) sc ON so.id = sc.id
    WHERE so.name = 'EgSys_ActualFreightMain' AND sc.name = 'UpdateBy'
)
BEGIN
    ALTER TABLE dbo.EgSys_ActualFreightMain ADD UpdateBy VARCHAR(50) NOT NULL DEFAULT ''
    EXEC sys.sp_addextendedproperty @name = N'MS_Description',
                                    @value = N'更新人',
                                    @level0type = N'SCHEMA',
                                    @level0name = N'dbo',
                                    @level1type = N'TABLE',
                                    @level1name = N'EgSys_ActualFreightMain',
                                    @level2type = N'COLUMN',
                                    @level2name = N'UpdateBy'
END;
GO