V = 视图 X = 扩展存储过程*/--数据库IFexists(SELECT1fromsys. sysdatabaseswherename=dbname)begindropdatabasedbnameend--表IFexists(SELECT1fromsys. sysobjectswhereid=object_id(N'tbname')ANDOBJECTPROPERTY(id, N'IsUserTable')=1)BEGINdropTABLEtbnameEND--存储过程IFexists(SELECT1fromsys. sysobjectsw...
ALTER TABLE products ADD COLUMN description text;新增的字段对于表中已经存在的行而言最初将先填充所给出的缺省值(如果你没有声明DEFAULT子句,那么缺省是空值)。 增加列(含约束) ALTER TABLE products ADD COLUMN description text CHECK (description <>''); 删除列 alter table 表名 drop column 列名 删除列(...
alter table t alter column c2 nvarchar(200) 範例程式碼 4-34:更動既有資料表的資料行類型時,小心是否導致大量 I/O 01 02 03 4-2 05 06 07 資料類型 14 這一點有人在大聲疾呼,一定要讓其變成可讀寫,你可以參考如下的網址: https://connect.microsoft.com/SQLServer/feedback/ViewFeedback.aspx?Feed...
Option 1: Check the column existence and add id 1 2 3 4 5 6 7 8 9 if not exists ( select column_name from INFORMATION_SCHEMA.columns where table_name = 'table_name' and column_name = 'new_column_name' ) ALTER TABLE table_name add new_column_name TEXT ...
drop column u_id; --3. 添加字段 alter table uinfor add u_note varchar(1) NULL; --4. 修改字段 --if exists(select * from syscolumns where id=object_id(N'uinfor') and name='u_key') alter table uinfor alter column u_key varchar(18) NOT NULL; ...
select column_name,data_type from information_schema.columns where table_name = '表名' 15 判断一个表是否存在 if exists(select 1 from sysobjects where name='要判断的表名' and xtype='U') print '在' else print '不在' 或者 if objectproperty(object_id('要判断的表名'),'isusertable') ...
|IF(COLUMNS_UPDATED(){bitwise_operator}updated_bitmask) {comparison_operator}column_bitmask[...n] }] sql_statement[...n] } }例子:创建了一个触发器,在 titles 表上创建一个插入、更新类型的触发器,其程序清单如下:USE pubsIF EXISTS (SELECT name FROM sysobjects WHERE name = 'reminder' AND type...
[ , ] ...n ] ] ) |FORTIMESTAMPASOF'<point_in_time>'}::={NOEXPAND[ ,INDEX(<index_value>[ , ...n ] ) |INDEX= (<index_value>) ] |INDEX(<index_value>[ , ...n ] ) |INDEX= (<index_value>) |FORCESEEK[ (<index_value>(<index_column_name>[ , ... ] ) ) ] |FORCESC...
Check If Column Is PRIMARY KEY Check if database exists? Check if Feb-29 is falling between start and end dates Check if file exists then delete it- fix code Check if installed SQL Server is an Eval copy Check if login has db_owner via user mappings on a specific database Check if ...
Check for valid Ip address Check if amount is positive or negative Check If Column Is PRIMARY KEY Check if database exists? Check if Feb-29 is falling between start and end dates Check if file exists then delete it- fix code Check if installed SQL Server is an Eval copy Check if login...