计算列不能作为PRIMARY KEY、UNIQUE、FOREIGN KEY或DEFAULT约束定义的一部分; 计算列不能用INSERT和UPDATE语句插入资料。 注意:① 在建表语句中,不允许对计算列设置空值属性(NULL或NOT NULL); ② 在建表语句中,列与列的定义用逗号分隔,当将PRIMARY KEY设置在最后时, 如果最后一列是常规列,则它后面的...
|{ ENABLE|DISABLE }TRIGGER{ALL|<触发器名>[, n]} |DROP--【删除列或约束】 {[CONSTRAINT]<约束名>--删除某个约束 |COLUMN<column_name>}[, n]--删除某列 |{CHECK|NOCHECK}CONSTRAINT{ALL|<约束名>[, n]} |{ENABLE|DISABLE}TRIGGER{ALL|<trigger_name>[, n]} |SWITCH[PARTITION ]...
6. How would you clear a table that foreign key constraints reference without adding to the server logs? DROPthe constraints,TRUNCATEthe table, and recreate the constraints. TRUNCATEthe table. DROPthe table and recreate the table with the new constraints. Disable the constraints,TRUNCATEthe table,...
Feature FOREIGN KEY Applies to: Azure SQL Database and SQL Server starting SQL Server 2016 (13.x)For memory-optimized tables, FOREIGN KEY constraints are only supported for foreign keys referencing primary keys of other memory-optimized tables. Remove the constraint from the table definition if th...
CheckConstraintDefinition CheckpointStatement ChildObjectName ClassifierEndTimeOption ClassifierImportanceOption ClassifierMemberNameOption ClassifierStartTimeOption ClassifierWlmContextOption ClassifierWlmLabelOption ClassifierWorkloadGroupOption CloseCursorStatement CloseMasterKeyStatement ...
CONSTRAINT ISOLATION SUBSTRING CONSTRAINTS JOIN SUM CONTINUE KEY SYSTEM_USER CONVERT LANGUAGE TABLE CORRESPONDING LAST TEMPORARY COUNT LEADING THEN CREATE LEFT TIME CROSS LEVEL TIMESTAMP CURRENT LIKE TIMEZONE_HOUR CURRENT_DATE LOCAL TIMEZONE_MINUTE CURRENT_TIME LOWER 收件人 CURRENT_TIMESTAM...
使用T-SQL进行数据定义 数据库技术与应用（电子商务系列）使用T-SQL进行数据定义 一、数据库定义 •（一）T-SQL语句创建数据库的语法格式 •CREATEDATABASE数据库名 //设置数据库的名称 •[ON //定义数据库的数据文件 •[PRIMARY]//设置主文件组 •<数据文件描述符>[,…n]//设置数据文件的属性 •...
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此时,将启用 FOREIGN KEY 约束。 复制代码 ALTER TABLE HumanResources.EmployeeDepartmentHistory CHECK CONSTRAINT FK_EmployeeDepartmentHistory_Department_DepartmentID; GO 1. 2. 3. H. 重新生成分区索引 以下示例重新生成分区索引IX_TransactionHistory_TransactionDate的单个分区,分区编号为5。此示例假定安装了已分区索...
Only if one dataset is correct and COULD be inserted, the INSERT goes on and the before insert trigger starts. Try it with: alter table PlanningT disable keys; und after the insert: alter table PlanningT enable keys; Regards AndreasNavigate...