标签：alt ted 问题 null 消息 varchar party 提示 padding
向已有表增加字段
执行下面sql，sql执行增加两个字段分别：
USE [tg_thirdparty] GO /****** Object: Table [dbo].[WX_Activity] Script Date: 10/31/2018 10:54:46 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO IF NOT EXISTS ( SELECT 1 FROM SYSOBJECTS T1 INNER JOIN SYSCOLUMNS T2 ON T1.ID = T2.ID WHERE T1.NAME = ‘WX_Activity‘ AND T2.NAME = ‘articleTitle‘ ) BEGIN ALTER TABLE [dbo].[WX_Activity] ADD [articleTitle] [nvarchar](200) NOT NULL --ALTER TABLE [dbo].[WX_Activity] ADD CONSTRAINT [DF_WX_Activity_articleTitle] DEFAULT (‘‘) FOR [articleTitle] --ALTER TABLE [dbo].[WX_Activity] ALTER COLUMN [articleTitle] [nvarchar](200) NOT NULL EXEC sys.sp_addextendedproperty @name = N‘MS_Description‘, @value = N‘正标题‘, @level0type = N‘SCHEMA‘, @level0name = N‘dbo‘, @level1type = N‘TABLE‘, @level1name = N‘WX_Activity‘, @level2type = N‘COLUMN‘, @level2name = N‘articleTitle‘ END GO IF NOT EXISTS ( SELECT 1 FROM SYSOBJECTS T1 INNER JOIN SYSCOLUMNS T2 ON T1.ID = T2.ID WHERE T1.NAME = ‘WX_Activity‘ AND T2.NAME = ‘articleSubTitle‘ ) BEGIN ALTER TABLE [dbo].[WX_Activity] ADD [articleSubTitle] [nvarchar](200) NOT NULL --ALTER TABLE [dbo].[WX_Activity] ADD CONSTRAINT [DF_WX_Activity_articleSubTitle] DEFAULT (‘‘) FOR [articleSubTitle] --ALTER TABLE [dbo].[WX_Activity] ALTER COLUMN [articleSubTitle] [nvarchar](200) NOT NULL EXEC sys.sp_addextendedproperty @name = N‘MS_Description‘, @value = N‘副标题‘, @level0type = N‘SCHEMA‘, @level0name = N‘dbo‘, @level1type = N‘TABLE‘, @level1name = N‘WX_Activity‘, @level2type = N‘COLUMN‘, @level2name = N‘articleSubTitle‘ END GO
提示错误
消息 4901，级别 16，状态 1，第 10 行 ALTER TABLE 只允许添加满足下述条件的列: 列可以包含 Null 值；或者列具有指定的 DEFAULT 定义；或者要添加的列是标识列或时间戳列；或者，如果前几个条件均未满足，则表必须为空以允许添加此列。不能将列"articleTitle"添加到非空表"WX_Activity"中，因为它不满足上述条件。 消息 4901，级别 16，状态 1，第 9 行 ALTER TABLE 只允许添加满足下述条件的列: 列可以包含 Null 值；或者列具有指定的 DEFAULT 定义；或者要添加的列是标识列或时间戳列；或者，如果前几个条件均未满足，则表必须为空以允许添加此列。不能将列"articleSubTitle"添加到非空表"WX_Activity"中，因为它不满足上述条件。
表中已经有数据了，不设置默认值，有要求字段不能为NULL，矛盾了！！
所以先指定默认值，插入字段时，加上默认值 DEFAULT ‘‘
USE [tg_thirdparty] GO /****** Object: Table [dbo].[WX_Activity] Script Date: 10/31/2018 10:54:46 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO IF NOT EXISTS ( SELECT 1 FROM SYSOBJECTS T1 INNER JOIN SYSCOLUMNS T2 ON T1.ID = T2.ID WHERE T1.NAME = ‘WX_Activity‘ AND T2.NAME = ‘articleTitle‘ ) BEGIN ALTER TABLE [dbo].[WX_Activity] ADD [articleTitle] [nvarchar](200) NOT NULL DEFAULT ‘‘ --ALTER TABLE [dbo].[WX_Activity] ADD CONSTRAINT [DF_WX_Activity_articleTitle] DEFAULT (‘‘) FOR [articleTitle] --ALTER TABLE [dbo].[WX_Activity] ALTER COLUMN [articleTitle] [nvarchar](200) NOT NULL EXEC sys.sp_addextendedproperty @name = N‘MS_Description‘, @value = N‘正标题‘, @level0type = N‘SCHEMA‘, @level0name = N‘dbo‘, @level1type = N‘TABLE‘, @level1name = N‘WX_Activity‘, @level2type = N‘COLUMN‘, @level2name = N‘articleTitle‘ END GO IF NOT EXISTS ( SELECT 1 FROM SYSOBJECTS T1 INNER JOIN SYSCOLUMNS T2 ON T1.ID = T2.ID WHERE T1.NAME = ‘WX_Activity‘ AND T2.NAME = ‘articleSubTitle‘ ) BEGIN ALTER TABLE [dbo].[WX_Activity] ADD [articleSubTitle] [nvarchar](200) NOT NULL DEFAULT ‘‘ --ALTER TABLE [dbo].[WX_Activity] ADD CONSTRAINT [DF_WX_Activity_articleSubTitle] DEFAULT (‘‘) FOR [articleSubTitle] --ALTER TABLE [dbo].[WX_Activity] ALTER COLUMN [articleSubTitle] [nvarchar](200) NOT NULL EXEC sys.sp_addextendedproperty @name = N‘MS_Description‘, @value = N‘副标题‘, @level0type = N‘SCHEMA‘, @level0name = N‘dbo‘, @level1type = N‘TABLE‘, @level1name = N‘WX_Activity‘, @level2type = N‘COLUMN‘, @level2name = N‘articleSubTitle‘ END GO
“xxxx”表 - 无法修改表。 不能将值 NULL 插入列 'xxxx'
标签：alt ted 问题 null 消息 varchar party 提示 padding
原文地址：https://www.cnblogs.com/Zev_Fung/p/9882077.html
