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.
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.
The COUNT() function returns the number of records in a tables based on sql query.
The COUNT function will only count those records in which the field in the brackets is NOT NULL.
The keyword ‘ORDER BY’ clause used in SQL to order the data sets retrieved from a SQL database.
The sorting of result set can be based on column or columns.
CREATE TABLE AS SELECT statement can be used when we need to extract part or full data from a table and store it into another table based on certain conditions
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
CREATE TABLE statement: create a table with composite primary key.
Oracle PL/SQL:CREATE TABLE statement: create a table with primary key.