add constraint
Such constraints are ignored until they are re-enabled by using ALTER TABLE table WITH CHECK CHECK CONSTRAINT ALL . ADD Specifies that one or more column definitions, computed column definitions, or table constraints are added, or the columns that the sy,ALTER TABLE sales ADD CONSTRAINT sales_pk PRIMARY KEY(cust_id,prod_id,prom_id);. 刪除, ALTER TABLE customer. DROP CONSTRAINT pk_PersonID; or 刪除與主鍵相關的所有值. ALTER TABLE CUSTOMERS DROP PRIMARY KEY CASCADE. 項目, FOREIGN KEY : 外鍵限制單一, FOREIGN KEY : 外鍵限制複合.
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 add constraint 相關參考資料
Adding Constraints
Table-Constraint—Use this syntax when you add a constraint after a column definition in a CREATE TABLE statement, or when you add, alter, or drop a constraint on a column using ALTER TABLE. HP Vertica... https://my.vertica.com ALTER TABLE (Transact-SQL) | Microsoft Docs
Such constraints are ignored until they are re-enabled by using ALTER TABLE table WITH CHECK CHECK CONSTRAINT ALL . ADD Specifies that one or more column definitions, computed column definitions, or ... https://docs.microsoft.com CONSTRAINT SQL運用@ oracle園地:: 痞客邦::
ALTER TABLE sales ADD CONSTRAINT sales_pk PRIMARY KEY(cust_id,prod_id,prom_id);. 刪除, ALTER TABLE customer. DROP CONSTRAINT pk_PersonID; or 刪除與主鍵相關的所有值. ALTER TABLE CUSTOMERS DROP PRIMARY KEY CASCADE. ... http://oracled2k.pixnet.net SQL - ADD CONSTRAINT | 1Keydata
The 1Keydata SQL Tutorial teaches beginners the building blocks of SQL. This section explains how to add a constraint to a table. https://www.1keydata.com SQL CHECK Constraint - W3Schools
To create a CHECK constraint on the "Age" column when the table is already created, use the following SQL: MySQL / SQL Server / Oracle / MS Access: ALTER TABLE Persons ADD CHECK (Age>=18)... https://www.w3schools.com SQL FOREIGN KEY Constraint - W3Schools
To create a FOREIGN KEY constraint on the "PersonID" column when the "Orders" table is already created, use the following SQL: MySQL / SQL Server / Oracle / MS Access: ALTER TABLE ... https://www.w3schools.com SQL PRIMARY KEY Constraint - W3Schools
To create a PRIMARY KEY constraint on the "ID" column when the table is already created, use the following SQL: MySQL / SQL Server / Oracle / MS Access: ALTER TABLE Persons ADD PRIMARY KEY (... https://www.w3schools.com SQL UNIQUE Constraint - W3Schools
To create a UNIQUE constraint on the "ID" column when the table is already created, use the following SQL: MySQL / SQL Server / Oracle / MS Access: ALTER TABLE Persons ADD UNIQUE (ID);. To n... https://www.w3schools.com 建立唯一的條件約束| Microsoft Docs
... constraint, and click Design. 在[資料表設計工具] 功能表上，按一下[索引/索引鍵]。On the Table Designer menu, click Indexes/Keys. 在[索引/索引鍵] 對話方塊中，按一下[加入]。In the Indexes/Keys dialog box, click Add. 在[一般] 底下的方格中，按一下[類型]，然... https://docs.microsoft.com |