SQL query use for both INSERT into values and SELECT to save time.
SQL round and truncate decimal functions used in banking project.
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.
Two kinds of Joins equi join and inner join mostly a confusion to all SQL developers. The given clear differences highly useful so that a basic learner can understand quickly.