其中包括用户定义类型变量或函数以及用户定义函数,但不能引用 Transact-SQL 语句。 partition_number 必须存在,否则,该语句将失败。 WITH ( <single_partition_rebuild_index_option> ) SORT_IN_TEMPDB、MAXDOP、DATA_COMPRESSION和XML_COMPRESSION 是使用 (PARTITION = partition_number) 语法重新生成单个分区时可以指定...
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 アクセス許可 サービスブローカー SET xQuery (XMLデータベース操作言語) PDF をダウンロード Learn...
ALTERTABLE[IFEXISTS]table_name {ADD{<schema_component>|(<schema_component>[,...])}|MODIFY{<schema_component>|(<schema_component>[,...])}|DROP{column_name|(column_name,column_name,...)|PRIMARYKEY|CONSTRAINTconstraint_name|WATERMARK}|RENAMEold_column_nameTOnew_column_name|RENAMETOnew_table_...
ROWGUIDCOL和IDENTITY列属性可能错误地命名为约束。 例如,CREATE TABLE T (C1 int CONSTRAINT MyConstraint IDENTITY)语句可以执行,但约束名不会保留,也无法让用户访问。ROWGUIDCOL和IDENTITY列属性不能命名为约束。 返回错误 156。低 使用双向赋值(如UPDATE T1 SET @v = column_name = <expression>)来更新列会产生...
The PRIMARY KEY constraint in the user table can't be modified while a spatial index is defined on a column of that table. To change the PRIMARY KEY constraint, first drop every spatial index of the table. After modifying the PRIMARY KEY constraint, you can re-create each of the spatial...
VALIDATE CONSTRAINT constraint_name 验证一个外键或是一个使用NOT VALID选项创建的检查类约束,通过扫描全表来保证所有记录都符合约束条件。如果约束已标记为有效时,什么操作也不会发生。 DROP CONSTRAINT [ IF EXISTS ] constraint_name [ RESTRICT | CASCADE ] 删除一个表上的约束。 CLUSTER ON index_name 为...
To enable a UNIQUE or PRIMARY KEY constraint, you must have the privileges necessary to create an index on the table. You need these privileges because Oracle creates an index on the columns of the unique or primary key in the schema containing the table. To enable or disable triggers, ...
Recommendations and guidelines for the "max degree of parallelism" configuration option in SQL Server(适用于 SQL Server 中的“max degree of parallelism”配置选项的建议和指南) LEGACY_CARDINALITY_ESTIMATION 资源 基数估计 (SQL Server) 使用SQL Server 2014 基数估算器优化查询计划 ...
SQL Statements: ALTER SESSION to ALTER SYSTEM, 3 of 3ALTER SYSTEM Purpose Use the ALTER SYSTEM statement to dynamically alter your Oracle instance. The settings stay in effect as long as the database is mounted. Prerequisites You must have ALTER SYSTEM system privilege. To specify the ...
(2,'Mary Smith',75000); -- This insert violates the constraint. INSERT INTO dbo.cnst_example VALUES (3,'Pat Jones',105000); -- Disable the constraint and try again. ALTER TABLE dbo.cnst_example NOCHECK CONSTRAINT salary_cap; INSERT INTO dbo.cnst_example VALUES (3,'Pat Jones',105000);...