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This tutorial shows you how to use Oracle PRIMARY KEY constraint to create, add, disable, enable, and drop a primary key of a table.
2 Ιουλ 2012 · INSERT INTO name_of_table( primary_key_column, <<other columns>> ) VALUES( name_of_sequence.nextval, <<other values>> ); Or you can define a trigger that automatically populates the primary key value using the sequence
The syntax to create a primary key using the ALTER TABLE statement in Oracle/PLSQL is: ALTER TABLE table_name ADD CONSTRAINT constraint_name PRIMARY KEY (column1, column2, ... column_n); Example. Let's look at an example of how to create a primary key using the ALTER TABLE statement in Oracle.
Oracle PRIMARY KEY Constraint with Examples. In this article, we will be learning about the Primary constraints and how to create, alter, drop or enable/disable them in Oracle. What is a Primary Key? The Primary Key constraint is used for uniquely identifying each row of a table.
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 (ID);
Composite Primary Key Example. The following statement defines a composite primary key on the combination of the prod_id and cust_id columns of the sample table sh.sales: ALTER TABLE sales ADD CONSTRAINT sales_pk PRIMARY KEY (prod_id, cust_id) DISABLE;
This creates a function-based unique index to enable case-insensitive uniqueness of EMAIL_ADDRESS . ... To add an unvalidated primary key (or unique constraint), you need to police it with a non-unique index. ... Database on OTN SQL and PL/SQL Discussion forums Oracle Database
