SELECT statement

Use the SELECT statement to specify which columns you're requesting. Follow the SELECT statement with the column expressions (similar to field names) you want to retrieve (for example, last_name). Expressions can include mathematical operations or string manipulation (for example, SALARY * 1.05).

The SELECT statement can use a variety of clauses:

SELECT [DISTINCT] {* | column_expression [[AS] column_alias],...}
FROM table_name [table_alias], ...
[ WHERE expr1 rel_operator expr2 ]
[ GROUP BY {column_expression, ...} ]
[ HAVING expr1 rel_operator expr2 ]
[ UNION [ALL] (SELECT...) ]
[ ORDER BY {sort_expression [DESC | ASC]}, ... ]
[ OFFSET n {ROWS | ROW} ]
[ FETCH FIRST [ n [ PERCENT ] ] { ROWS | ROW } {ONLY | WITH TIES } ]
[ FOR UPDATE [OF {column_expression, ...}] ]

Items in brackets are optional.

column_alias can be used to give the column a more descriptive name, or to abbreviate a longer column name.

SELECT dept AS department FROM emp

Field names can be prefixed with the table name or the table alias. For example, EMP.LAST_NAME or E.LAST_NAME, where E is the alias for the table EMP.

The DISTINCT operator can precede the first column expression. This operator eliminates duplicate rows from the result of a query.

SELECT DISTINCT dept FROM emp