Contents
What is a composite foreign key in Oracle?
If a FOREIGN KEY is applied on multiple columns, called a composite FOREIGN KEY. A Table or VIEW which contains the FOREIGN Key is known as child object and if FOREIGN Key column (s) references the TABLE or VIEW is known as PARENT object. The same TABLE or VIEW can contain FOREIGN KEY and REFERENCE KEY.
What do you call a table with a foreign key?
A Table or VIEW which contains the FOREIGN Key is known as child object and if FOREIGN Key column (s) references the TABLE or VIEW is known as PARENT object. The same TABLE or VIEW can contain FOREIGN KEY and REFERENCE KEY.
How to materialized view with primary key in SQL?
SQL> alter materialized view MyMV add constraint PK_ID primary key (id); Materialized view altered. SQL> alter table t3 add constraint FK_TABLE3_MyMV foreign key (id) references MyMV (id); Table altered.
What is referential intigrity constraint in Oracle foreign key?
An Oracle FOREIGN key called REFERENTIAL INTIGRITY CONSTRAINT. A FOREIGN KEY column makes a relationship with a specified PRIMARY or UNIQUE KEY. If a FOREIGN KEY is applied on multiple columns, called a composite FOREIGN KEY.
What do you call a column with a foreign key?
A FOREIGN KEY column makes a relationship with a specified PRIMARY or UNIQUE KEY. If a FOREIGN KEY is applied on multiple columns, called a composite FOREIGN KEY. A Table or VIEW which contains the FOREIGN Key is known as child object and if FOREIGN Key column (s) references the TABLE or VIEW is known as PARENT object.
How to define a composite primary key in Oracle?
1.create a unique+not null constraint on the parent table’s column that you want to refer. 2. make your child table’s column refer this column. you just need unique, the not null is not necessary. Tip: If you have a primary key such that some subset of that primary key is itself unique, you have done your model wrong.