Dropping the Primary Key removes both the Primary Keys and Clustered or Non-clustered indexes created along with the Primary key creation: Modify the Primary Key In SQL Server, there are no direct commands to modify Primary keys. We need to Drop an existing Primary Key and recreate it with n...
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...
語句DROP INDEX不適用於定義 或 UNIQUE 條件約束所建立的PRIMARY KEY索引。 若要移除條件約束和對應的索引,請使用 ALTER TABLE 搭配DROP CONSTRAINT 子句。重要 中<drop_backward_compatible_index> 定義的語法將會在未來的 SQL Server 版本中移除。 請避免在新的開發工作中使用這個語法,並規劃修改目前在使用這個語法...
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...
DROP a PRIMARY KEY Constraint To drop a PRIMARY KEY constraint, use the following SQL: SQL Server / Oracle / MS Access: ALTERTABLEPersons DROPCONSTRAINTPK_Person; MySQL: ALTERTABLEPersons DROPPRIMARYKEY; DROP a FOREIGN KEY Constraint To drop a FOREIGN KEY constraint, use the following SQL: ...
id INT PRIMARY KEY, customer_id INT, order_date DATE, product_id INT, quantity INT ) PARTITION BY LIST (customer_id) ( PARTITION p1 VALUES (100), PARTITION p2 VALUES (200), PARTITION p3 VALUES (300), PARTITION p4 VALUES (400), ...
In SQL Server, the FileTables feature uses a directory structure to store files. Learn how to create a new FileTable or alter or drop an existing FileTable.
DROP INDEX 陳述式不適用於利用定義 PRIMARY KEY 或 UNIQUE 條件約束而建立的索引 (使用 CREATE TABLE 或 ALTER TABLE 陳述式的 PRIMARY KEY 或 UNIQUE 選項建立)。如需 PRIMARY KEY 或 UNIQUE 條件約束的詳細資訊,請參閱<CREATE TABLE (SQL Server Compact Edition)>。
DROP TABLE cannot be used to drop a table that is referenced by a FOREIGN KEY constraint. The referencing FOREIGN KEY constraint or the referencing table must first be dropped. If both the referencing table and the table that holds the primary key are being dropped in the same DROP TABLE st...
Key Details About Disabling and Dropping SQL Server Indexes Let’s look at some “must-know” information about disabling and dropping indexes. Be aware if you disable a clustered index Prevents access to the data. The data remains intact but inaccessible until the clustered index is dropped or...