Selecting and Arranging Rows

You can select and arrange specific rows in the query.

Prerequisites

You can use the demo data for the SQL tutorial. Start the Database Studio as database administrator MONA with the password RED and log on to demo database DEMODB: Logging On to a Database.

Activities

You can use Database Studio to enter and execute SQL statements. More information: Working with SQL Statements: Overview

Selecting Specific Rows

To select specific rows, use the WHERE clause.

SELECT zip, name

FROM hotel.city

WHERE name = 'Seattle'

Selecting the rows with the city name Seattle

Result

`ZIP`	`NAME`
`20005`	`Seattle`
`20019`	`Seattle`
`20037`	`Seattle`

See also: SQL Reference Manual, WHERE Clause

SELECT rowno, cno, title, firstname, name

FROM hotel.customer

WHERE ROWNO <= 5

Selecting the first five rows and numbering the rows

Result

`ROWNO`	`CNO`	`TITLE`	`FIRSTNAME`	`NAME`
`1`	`3000`	`Mrs`	`Jenny`	`Porter`
`2`	`3100`	`Mr`	`Peter`	`Brown`
`3`	`3200`	`Company`	`?`	`Datasoft`
`4`	`3300`	`Mrs`	`Rose`	`Brian`
`5`	`3400`	`Mrs`	`Mary`	`Griffith`

See also: SQL Reference Manual, ROWNO Predicate (rowno_predicate)

Arranging the Rows

To arrange the rows, use the ORDER clause that specifies the order in which the rows are to appear.

SELECT name, firstname

FROM hotel.customer

WHERE ROWNO <= 5

ORDER BY name

Sorting the first five rows in alphabetical order by customer name

Result

`NAME`	`FIRSTNAME`
`Brian`	`Rose`
`Brown`	`Peter`
`Datasoft`	`?`
`Griffith`	`Mary`
`Porter`	`Jenny`

SELECT name, firstname

FROM hotel.customer

WHERE ROWNO <= 5

ORDER BY name DESC

Sorting the first five rows alphabetically by customer name, in descending order

Result

`NAME`	`FIRSTNAME`
`Porter`	`Jenny`
`Griffith`	`Mary`
`Datasoft`	`?`
`Brown`	`Peter`
`Brian`	`Rose`

Instead of the sort column name, you can also specify the position number in the output list (that is, ORDER BY 1 DESC instead of ORDER BY name DESC).

Unless otherwise stated, sort columns are always sorted in ascending order. A sort column does not necessarily also have to be an output column.

See also: SQL Reference Manual, ORDER Clause (order_clause)

Arranging Rows by More Than One Column

If you want to stagger the sort sequence, you can specify the sort column names in order of importance; each name can be assigned the add-on ASC or DESC, or both.

SELECT zip, name

FROM hotel.city

WHERE ROWNO < 5

ORDER BY name, zip DESC

Displaying the city/place data, sorted by name and in descending order by zip code

Result

`ZIP`	`NAME`
`12203`	`Albany`
`11788`	`Long Island`
`10580`	`New York`
`10019`	`New York`

Displaying Tables Without Duplicate Rows

You can prevent redundant information from being displayed in the query result. Specify the keyword DISTINCT after the keyword SELECT.

SELECT DISTINCT name, state

FROM hotel.city

ORDER BY name

Displaying the place/city data consisting of a different name and state

Result

`NAME`	`STATE`
`Albany`	`NY`
`Chicago`	`IL`
`Cincinnati`	`OH`
`Clearwater`	`FL`
`Dallas`	`TX`
`Daytona Beach`	`FL`
`Deerfield Beach`	`FL`
`Detroit`	`MI`
`Hollywood`	`CA`
`Irvine`	`CA`
`Long Beach`	`CA`
`Long Island`	`NY`
`Los Angeles`	`CA`
`New York`	`NY`
`Palm Spring`	`CA`
`Portland`	`OR`
`Rosemont`	`IL`
`Santa Clara`	`CA`
`Seattle`	`WA`
`Silver Spring`	`MD`

For comparison purposes, execute the SQL statement without specifying the keyword DISTINCT.

See also: SQL Reference Manual, DISTINCT Specification (distinct_spec)

More Information

SQL Reference Manual, QUERY Expression (query_expression), Selected Column (select_column), Table Expression (table_expression)

More examples for Data Query