Views

The View are a tables that are taken or derived from other table. View is in the SQL is a logical subset of a data from one or more table. A view themselves do not contain data. It is used to restrict data access. Create the view used the CREATE command. Syntax: CREATE OR REPLACE …

SQL Join

SQL have a powerful capability to retrieve data from the table using single command. This process is called Join. In Join, table are listed in the WHERE/FROM clause. Syntax: SELECT , = FROM , WHERE = ; Equi join :- In the join, joining condition is based on equality between values the common column is …

Simple Queries in SQL

Queries are one of a thing that make database powerful. The "Query" refers to action of retrieving data from the database. There are following some common clauses used in SQL. SELECT :- SELECT clause used to retrieves data from the table. SELECT command also provides the query capability this means that executing SELECT statement, information …

Nested Queries of SQL

This nested queries is in the SQL SELECT statement inside another SELECT or action query. The SQL first evaluates the inner query. The result of an inner query is returned to the outer query. Syntax SELECT EMPLOYEE_NAME FROM EMPLOYEE WHERE DEPT_code=select DEPT_code FROM EMPLOYEE WHERE EMPLOYEE_name='<'raju'>'; There are following some operators used in nested query. …

Datatypes of SQL

Every field or column in a table is given the database, when table is defined there data types describe a kind of information that can be store in a column. The most common datatypes are: CHAR (size) :- The column defied with CHAR datatype is allowed to store all types of character including letters both …

SQL

Structure Query Language :- SQL is a language. It is provides an interface to relational database system. SQL was developed by IBM in 1970 used to store and manage data in relational database management system. SQL also used to preform all types of operation likes, Inserting, Updating, Deleting, Creating and Modifying tables. Processing capabilities of …

Function Dependencies

Function dependencies are the consequence of a interrelationship among attribute of an entity represented by a relation. Function dependencies may also be due to the relationship between entities that are also represented by a relation. A relation R, attribute Y of R is a function dependencies. An attribute X of R if and only if each X value on …