Index is popular object in DB2 SQL. Popular questions to your instant knowledge given for quick reference.
Resolution to solve SQL ambiguous column quickly useful to all SQL developers.
Sub queries you can give at four places in main query. Those are SELECT, WHERE, HAVING and in FROM clause. To understand these examples clearly you must listen few tips here.
Sub queries are like queries with in the query. You can write subquery such that it will return single value or multiple values. Read more example and explanation.
The main benefit of SQL is you can join multiple tables and get the result. Two kinds of Joins equi join and inner join mostly a confusion to all SQL developers. The given clear differences highly useful and a basic learner can understand quickly.
SQL query is executed in two phases. The number one is Query processor and the other one is storage engine.