ALTER TABLE 语句的语法格式为: ALTERTABLEtable {[ALTER COLUMN column_name { new_data_type [ (precision[, scale]) ] [NULL | NOT NULL] |{ADD|DROP}ROWGUIDCOL } ] |ADD {[<column_definition>] |column_nameAScomputed_column_expression }[, n] |[WITH CHECK | WITH NOCHECK]ADD {}[, n] ...
ALTERTABLEtable_name {[ALTER COLUMN <column_name> {[<schema of new data type>].<new_data_type>[(precision [,scale])]max|<xmlschemacollection>[COLLATE <collation_name>][NULL | NOT NULL]|[{ADD | DROP} ROWGUIDCOL]|PERSISTED}]|ADD<columnname><data_type>[[DEFAULT <constant_expression>]|...
select*from test where 基本工资<10000or 基本工资>20000#查询表中基本工资低于10000或高于20000的员工所有信息 select*from test where 基本工资in(8000,9000,10000)#查询表中工资为8000,9000,和10000的员工所有信息。 select*from test where ×××号 like'66%'#查询test表中×××号以66开头的员工所有信息。
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...
–1. IDENTIY 列不能为空,不能设默认值,创建后不能使用ALTER TABLE TableName ALTER COLUMN修改,每张表只能有一个自增列 –2. 查看当前值:SELECT IDENT_CURRENT(‘TableName’), — 查看增量值:SELECT IDENT_INCR(‘TableName’) — 查看原始种子值:SELECT IDENT_SEED(‘TableName’),起始值, TRUNCATE TABL...
练习一:使用ALTER TABLE来添加和修改列 Examine the following CREATE TABLE statement, from the TSQL2012.sql script, that is used to create the Production.Categories table. 从TSQL2012.sql脚本开始,测试下面的CREATE TABLE语句,它是用来创建一个Production.Categories表。
where =object_id('表名') and a.xtype=b.xtype 把“表名”替换成你要查看字段类型的表名,比如你要查看sysobjects表的各字段类型那么就是 select as [column], as type from syscolumns a,systypes b where =object_id('sysobjects') and a.xtype=b.xtype ...
Error when trying to alter column type Error while attaching data from the SQL server management studio 2012 Error while creating clustered index view Error while creating View Error While enahling CDC(Change data capture) on Table. Error while executing sp_OAMethod Send Error while inserting rec...
AlterCertificateStatementKind AlterColumnAlterFullTextIndexAction AlterColumnEncryptionKeyStatement AlterCreateEndpointStatementBase AlterCreateServiceStatementBase AlterCredentialStatement AlterCryptographicProviderStatement AlterDatabaseAddFileGroupStatement AlterDatabaseAddFileStatement AlterDatabaseAuditSpe...
ALTER TABLE employees DROP COLUMN middle_name; 重命名表 更改表的名称: ALTER TABLE employees RENAME TO staff; 添加约束 向表中添加主键、外键、唯一性等约束: -- 添加主键 ALTER TABLE employees ADD CONSTRAINT pk_employee_id PRIMARY KEY (employee_id); -- 添加外键 ALTER TABLE orders ADD CONSTRAIN...