Difference between revisions of "SELECT"
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<table border='1'> | <table border='1'> | ||
<caption>games</caption> | <caption>games</caption> | ||
| − | <tr> <th>yr</th> <th>city</th> </tr> | + | <tr> <th>yr</th> <th>city</th> <th>y1</th></tr> |
| − | <tr> <td align='right'>2000</td> <td>Sydney</td> </tr> | + | <tr> <td align='right'>2000</td> <td>Sydney</td> <td></td></tr> |
| − | <tr> <td align='right'>2004</td> <td>Athens</td> </tr> | + | <tr> <td align='right'>2004</td> <td>Athens</td> <td>2000</td></tr> |
| − | <tr> <td align='right'>2008</td> <td>Beijing</td> </tr> | + | <tr> <td align='right'>2008</td> <td>Beijing</td><td>2004</td> </tr> |
| − | <tr> <td align='right'>2012</td> <td>London</td> </tr> | + | <tr> <td align='right'>2012</td> <td>London</td><td>2008</td> </tr> |
</table> | </table> | ||
<div class=qu> | <div class=qu> | ||
| Line 20: | Line 20: | ||
</div> | </div> | ||
<div class=setup> | <div class=setup> | ||
| − | CREATE TABLE games(yr INT, city VARCHAR(20)); | + | CREATE TABLE games(yr INT, city VARCHAR(20),y1 INT); |
INSERT INTO games(city,yr) VALUES ('Sydney',2000); | INSERT INTO games(city,yr) VALUES ('Sydney',2000); | ||
| − | INSERT INTO games(city,yr) VALUES ('Athens',2004); | + | INSERT INTO games(city,yr,y1) VALUES ('Athens',2004,2000); |
| − | INSERT INTO games(city,yr) VALUES ('Beijing',2008); | + | INSERT INTO games(city,yr,y1) VALUES ('Beijing',2008,2004); |
| − | INSERT INTO games(city,yr) VALUES ('London',2012); | + | INSERT INTO games(city,yr,y1) VALUES ('London',2012,2008); |
</div> | </div> | ||
<div class=def> | <div class=def> | ||
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===See also:=== | ===See also:=== | ||
| − | *[ | + | *[[SELECT_basics | SELECT Tutorial]] - practice using the SELECT command |
| − | *[[SELECT ... WHERE]] - the WHERE clause allows you to get some rows but not others | + | *[[SELECT_.._WHERE |SELECT ... WHERE]] - the WHERE clause allows you to get some rows but not others |
Revision as of 08:03, 3 January 2013
A SELECT statement gets data from a table. Each table contains rows and columns - you can SELECT some columns and ignore others
- The column names on the select line control which columns you get
- The FROM clause controls which table you access
schema:scott
The table games shows the year and the city hosting the Olympic Games.
| yr | city | y1 |
|---|---|---|
| 2000 | Sydney | |
| 2004 | Athens | 2000 |
| 2008 | Beijing | 2004 |
| 2012 | London | 2008 |
The SELECT statement returns results from a table.
In this example the table is games and the columns are
yr and city.
DROP TABLE games;
CREATE TABLE games(yr INT, city VARCHAR(20),y1 INT); INSERT INTO games(city,yr) VALUES ('Sydney',2000); INSERT INTO games(city,yr,y1) VALUES ('Athens',2004,2000); INSERT INTO games(city,yr,y1) VALUES ('Beijing',2008,2004); INSERT INTO games(city,yr,y1) VALUES ('London',2012,2008);
SELECT yr, city FROM games
See also:
- SELECT Tutorial - practice using the SELECT command
- SELECT ... WHERE - the WHERE clause allows you to get some rows but not others
