Tagged: SQL

You often need to fetch a row that has maximum value for a specific column. For example, we have an ORDERS table and we want...

Oracle database has syntax “CREATE TABLE … AS SELECT … “which allows you copy data from one table to another without predefining the target table....

In oracle, you can create Auto Increment column using sequence database object. Using Oracle sequence object you can generate unique value and assign that value...

Oracle database has a pseudo-column named ROWNUM. You can use this ROWNUM in your SQL query to limit the results You can use query like...

You often want to query an oracle database to list out all the tables in a database. In Oracle, there are mainly 3 different types...

NVL Function NVL function allow you to check an expression whether it is NULL or not.  If the expression is NULL then NVL function substitutes...

SQL WITH Clause was introduced by oracle in oracle 9.2 release. SQL WITH clause also known as subquery factoring. WITH clause will create temporary dataset...

An Inline View is a SELECT statement written in the FROM clause of a query. Inline View are used in ORACLE SQL to simplify complex...

In Correlated Subquery, inner query depends on outer query. Correlated Subquery is executed once for each row processed by the outer query. Correlated Subquery references...

In Noncorrelated subquery, inner query does not depend on outer query. Noncorrelated subquery can be categorized as follows Single row subquery / Scalar Subquery Multiple...