On this SQL Server exception message, we can learn that the SQL Check constraint name is CK__Customer__Custom__71D1E811. Error detail gives the database name, as well as the table and the column name where the SQL check constraint is defined. If SQL programmer has to drop SQL constra...
CONSTRAINT [ IF EXISTS ] name 删除由名称标识的主键、外键或 CHECK 约束。 CHECK 约束只能按名称删除。 RESTRICT 或CASCADE 如果指定 RESTRICT 并且主键由任何外键引用,则语句将失败。如果指定 CASCADE,则删除主键会导致删除任何引用该表的外键。默认为 RESTRICT。 IF EXISTS 如果指定 IF EXISTS,如果表...
CheckConstraintDefinition CheckpointStatement ChildObjectName ClassifierEndTimeOption ClassifierImportanceOption ClassifierMemberNameOption ClassifierStartTimeOption ClassifierWlmContextOption ClassifierWlmLabelOption ClassifierWorkloadGroupOption CloseCursorStatement CloseMasterKeyStatement CloseSymmetricKeyStatement Coa...
To drop a check constraint from a table in PostgreSQL, you can use the ALTER TABLE statement. The ALTER TABLE statement is used to modify the structure of an existing table in the database. Here’s the syntax to drop a check constraint from a table: Syntax ALTER TABLE table_name DROP ...
ALTER 语句 (Transact-SQL) CREATE 语句 (Transact-SQL) DISABLE TRIGGER (Transact-SQL) DROP 语句 (Transact-SQL) DROP 语句 (Transact-SQL) DROP AGGREGATE (Transact-SQL) DROP APPLICATION ROLE (Transact-SQL) DROP ASSEMBLY (Transact-SQL) DROP ASYMMETRIC KEY (Transact-SQL) ...
sql_variant类型可以用来存储除了text,ntext,image,timestamp和sql_variant之外的所有SQL Server 2008支持的数据类型,其主要用于列、参数、变量和用户定义函数的返回值中。当某个字段需要存储不同类型的数据时,可以将其设置为sql_variant类型。table类型是一种特殊的数据类型,用于存储结果集以便于后续的处理。table类型...
Subclause 11.26, "<drop table constraint definition>": <drop table constraint definition> ::= DROP CONSTRAINT <constraint name> <drop behavior> ... Conformance Rules Without Feature F381, "Extended schema manipulation", conforming SQL language shall not contain a <drop table constraint defi...
该DROP INDEX语句不适用于通过定义PRIMARY KEY或UNIQUE约束创建的索引。 若要删除约束和相应的索引,请使用ALTER TABLE和DROP CONSTRAINT子句。 重要 将在SQL Server 的未来版本中删除定义的<drop_backward_compatible_index>语法。 请避免在新的开发工作中使用该功能,并考虑修改当前使用该功能的应用程序。 请改用在<dro...
We cannot remove a column with a CHECK constraint in the table. If we want to drop a column with constraints, we first remove the constraint.SQL Serverdoes not drop a column with PRIMARY or FOREIGN KEY constraints or other dependencies. However, we can do this by using the Table Designer...
A function that is referenced in a generated column expression or a check constraint (SQLSTATE 42893) RESTRICT The RESTRICT keyword enforces the rule that the function is not to be dropped if any of the following dependencies exists: Another function is sourced on the function. Another routine...