2.28 ORDER BY CLAUSE

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Description

The ORDER BY clause specifies the sorting of rows retrieved by the SELECT statement. SQL does not guarantee the sort order of rows unless the SELECT statement includes an ORDER BY clause.

Syntax

ORDER BY { expr | posn } [ ASC | DESC ]

[ , { expr | posn } [ASC | DESC] ,... ]

Notes

Ascending order is the default ordering. The descending order will be used only if the keyword DESC is specified for that column.
Each expr is an expression of one or more columns of the tables specified in the FROM clause of the SELECT statement. Each posn is a number identifying the column position of the columns being selected by the SELECT statement.
The selected rows are ordered on the basis of the first expr or posn and if the values are the same then the second expr or posn is used in the ordering.
The ORDER BY clause if specified should follow all other clauses of the SELECT statement.
A query expression followed by an optional ORDER BY clause can be specified. In such a case, if the query expression contains set operators, then the ORDER BY clause can specify only the positions. For example:

-- Get a merged list of customers and suppliers

-- sorted by their name.

(SELECT name, street, state, zip

FROM customer

UNION

SELECT name, street, state, zip

FROM supplier)

ORDER BY 1 ;

Example

SELECT name, street, city, state, zip

FROM customer

ORDER BY name ;