The SELECT Statement

Select statement retrieves data from database. The set of data retrieved via select statement is referred to as result set.

Syntax:

Select <one or more Column names>

From <One or more table names>

Where <one or more condition apply>

The result sets generated by queries contains columns from one or more tables. While most elements in SELECT clauses will typically be simple column references, a SELECT clause may also include:

• Literal Values, such as numbers (1) or strings (‘abc’)
• Expressions, such as length * 3.14
• Functions, such as TO_DATE(’01-Jan-2013’,’DD-MON-YYYY)
• Pseudo columns, such as ROWID, ROWNUM or LEVEL

     For example

SELECT 1 num, 'abc' str

FROM customer;