Oracle Tables: CREATE TABLE statement: create a table with primary key.
CREATE TABLE statement is used to create table objects in database.You can create tables with different column data types.It is possible to add CONSTRAINTS like primary key ,foreign key etc while creating the table or can be added after the table creation.
Oracle Tables: Foreign Keys with ON DELETE CASCADE option.Foreign Keys with ON DELETE CASCADE option allows us to create parent child tables which automatically deletes referenced data in child tables when deleted from parent table.
Oracle: ORA-02449: unique/primary keys in table referenced by foreign keys
‘ORA-02292: integrity constraint violated – child record found’ error occurs when we try to delete a row from a parent table which is having a child table with foreign key constraint and the corresponding data exists in the child table.
ORA-02291: integrity constraint violated – parent key not found error occurs when we try to insert a row in a child table with a foreign key constraint and the related… Read more »
Foreign Key holds the reference to another table column value.It is also known as references constraint.
A foreign key means that values in one table must also appear in another table.
Composite primary key is a special type of primary key comprises a set of columns.In relational database a primary key is a candidate key to uniquely identify each row in a table.
In relational database a primary key is a candidate key to uniquely identify each row in a table.
A unique key or primary key comprises a single column or set of columns (COMPOSITE Primary KEY).
The MIN function returns the minimum value of an expression.MIN() function is reverse of MAX() function.MIN() function can be used along with GROUP BY clause also.