.SMO.DataType]::DateTime$col5=New-Object-TypeNameMicrosoft.SqlServer.Management.SMO.Column-argumentlist$tb,"ExpiryDate",$Type$col5.Nullable =$false$tb.Columns.Add($col5)#Run the Alter method to make the change on the instance of SQL Server.$tb.Alter()#Remove the table ...
但其确实有个约束: 'DF__HIS_DRUG___ALL_I__04E4BC85' . 为什么有这个约束呢??? 终于再搜索到这篇文章时,我明白了. 因为列'ALL_INVENTORY_STATE'在创建时赋值了默认值. 所以才有这个约束的. 参考: http://blog.csdn.net/rodjohnsondoctor/article/details/7486213 http://www.ithao123.cn/content-62...
BEGIN TRANSACTION IF exists (SELECT * FROM sys.columns c INNER JOIN sys.objects t ON (c.[object_id] = t.[object_id]) WHERE t.[object_id] = OBJECT_ID(N'[dbo].[MyTable]') AND c.[name] = 'ColumnName') BEGIN TRY ALTER TABLE [dbo].[MyTable] DROP COLUMN ColumnName END TRY BE...
增加和删除字段 1. 向stu表中插入qq字段: alter table stu add qq varchar(20) select * from stu 1. 2. 插入后查询结果为: 插入成功! 2. 删除stu表中的qq字段 alter table stu drop column qq select * from stu 1. 2. 删除后的查询结果为: 删除成功! 删除表 --创建一个临时表 create table tt...
修改字段的语法:alter table tablename modify (column datatype [default value][null/not null],….); 删除字段的语法:alter table tablename drop (column); 添加、修改、删除多列的话,用逗号隔开。 使用alter table 来增加、删除和修改一个列的例子。
今天在修改一个字段类型,由原来的 varchar(500) 增加到 varchar(1000) 则对应的SQL 语句,执行后如图错误 结果查下来是因为其中一个视图建成了索引视图, 解决办法:先将该视图删除,执行修改字段的语句,再创建视图 该视图增加 with schemabinding
SERVER CONFIGURATION SERVER ROLE SERVICE SERVICE MASTER KEY SYMMETRIC KEY TABLE TABLE column_constraint TABLE column_definition TABLE computed_column_definition TABLE index_option TABLE table_constraint TRIGGER User VIEW WORKLOAD GROUP XML SCHEMA COLLECTION バックアップと復元 CREATE 照合順序 DROP アクセ...
ALTERTABLEDUFEI_HEFEI_Spider_Data_20220714ALTERCOLUMN预售许可证NVARCHAR(255);CREATEINDEXidx_sPropertyPermitNoONDUFEI_HEFEI_Spider_Data_20220714(项目总期名称,预售许可证); 四、怎么截取某个字符之前的字符? 例如---“第8层(共12层)”---怎么截取“(”之前的字符?即取出“第8层”这个字符 SELECT...
I've found several sources that state ALTER TABLE ... DROP COLUMN is a meta-data only operation. Source How can this be? Does the data during a DROP COLUMN not need to be purged from the underlying non-clustered indexes and clustered index / heap? In addition, why do the ...
ALTER TABLE modifies a table definition by altering, adding, or dropping columns and constraints. ALTER TABLE also reassigns and rebuilds partitions, or disables and enables constraints and triggers.