CREATE INDEX statement is used to create Indexes using table columns.An index allows faster retrieval of records.It is mainly used as a performance-tuning method.An index creates an entry for each value that appears in the indexed columns.
Usage Create table statement with foreign key constraint will create table with referential integrity.
Foreign Key holds the reference to another table column value.
Oracle Tables: CREATE TABLE statement: create a table with primary key.
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.
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).
Usage Create table statement with foreign key constraint will create table with referential integrity
Foreign Key holds the reference to another table column value.It is also known as references constraint