SQL Server 表不使用默认值

问题描述

我正在使用 SSIS 包填充表格.

I am populating a table using an SSIS package.

这个想法是，每当包上传到表时，它都会使用 getdate() 对值进行时间戳.

The idea is that whenever the package uploads to the table, it will timestamp the value using getdate().

当我打开它时，我的 DDL 看起来是这样的:

My DDL looks like this when I open it up:

CREATE TABLE [REPORTING].[post_ssis_table_1](
    [validation_key] [int] IDENTITY(1,1) NOT NULL,
    [ssis_ran_date] [datetime] NULL,
    [server_name] [varchar](255) NULL,
    [data_base] [varchar](255) NULL,
--A bunch of other irrelevant columns
    [success_status] [varchar](255) NULL,
    [success_criteria] [varchar](255) NULL,
PRIMARY KEY CLUSTERED 
(
    [validation_key] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

ALTER TABLE [REPORTING].[post_ssis_tbl_1] ADD  DEFAULT (getdate()) FOR [ssis_ran_date]
GO

注意:我没有输入alter语句，这就是我打开DDL时的样子.

Note: I did not type the alter statement, that's literally what it looks like when I open up the DDL.

为什么在我插入行时没有为 [ssis_ran_date] 填充默认值?它实际上只是保持为空.

Why is the default value not populating for [ssis_ran_date] when I insert rows? It literally just stays null.

推荐答案

如果您的 INSERT 语句为具有默认值的列指定 NULL，则将插入 NULL.

If your INSERT statement specifies NULL for a column with a default, then NULL will get inserted.

只有在 INSERT 中根本没有指定该列时才会使用默认值.

The default will only be used when that column is not specified in the INSERT at all.

这篇关于SQL Server 表不使用默认值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持html5模板网！