Selecting and Arranging Rows
You can select and arrange specific rows in the query.
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.
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)
SQL Reference Manual, QUERY Expression (query_expression), Selected Column (select_column), Table Expression (table_expression)
More examples for Data Query