nested querieslet us see some more complex

Question

Nested Queries

Let us see some more complex queries in this section.

Sub-queries:

Some of the basic concerns of sub-queries are:

• A sub-query is a SELECT statement that is fixed in a clause of another SELECT statement. They are often referred to as a SUB SELECT or NESTED SELECT or INNER SELECT.
• The sub-query (inner query) implements first before the main query. The product of the sub-query is used by the outer query (main query).
• Sub-query can be placed in HAVING or WHERE or FROM clauses.
• Format of using sub-queries:

                 SELECT

                 FROM

                 WHERE expr OPERATOR

                                                          (SELECT FROM

WHERE);

                Operator has a comparison operator (one or multiple row operators)

Single row operator:   >, =, >=, <, <=, <>

                         Multiple row operators: IN, ALL, ANY,

• Order by clause can't be used in sub-query, if specified it must be the end clause in the main select statement.
• Parts of sub-queries:

         ‰  Single row sub-query: It gives only single row from the inner select statement.

        ‰   Multiple row sub-queries: It gives more than single row from the inner select statement

        ‰  Multiple column sub-queries: It gives more than single column from the inner select statement.

Single row operators are used with one row sub queries and multiple row operators are used with numerous row sub queries.

• The Inner and Outer queries can get data from different tables.
• Group Functions are used in sub queries.

View Complete Question

Request for Solution File

Ask an Expert for Answer!!

Database Management System: nested querieslet us see some more complex

Reference No:- TGS0209931

Expected delivery within 24 Hours

Have a Question? (oR Write a Review)

Write atleast 100 words!!

   Recent Questions Asked Database Management System

Q : if zrei find the value of eizsolution if zrei find the value of eizsolution

Q : in coordination compounds how to decide whether in coordination compounds how to decide whether itss hybridisation will be sp3d2 or d2sp3 itss based on inner or outer orbital complex but how will

Q : thorwarth m arisha a and harper p 2009 simulation thorwarth m arisha a and harper p 2009 simulation model to investigate flexible workload management for healthcare and servicescape environment

Q : a certain radioactive substance has a half-life a certain radioactive substance has a half-life of 40 minutes how much of an original 100 grams substance will remain after 2 hours solution m

Q : nested querieslet us see some more complex nested querieslet us see some more complex queries in this sectionsub-queriessome of the basic concerns of sub-queries are a sub-query is a select

Q : let consider the given partial relation emp let let consider the given partial relation emp let us make some sub-queries for

Q : 1 write two m-files one for the bisection method 1 write two m-files one for the bisection method and another for newtons method2 using both the bisection method and the newton method answer the

Q : a ram-air intake is any intake design which uses a ram-air intake is any intake design which uses the dynamic air pressure produced by vehicle motion to increase the static air pressure inside of

Q : there are two major differences between center of there are two major differences between center of gravity and center of mass1 the term center of gravity aplies to the bodies with mass and weight