Difference between revisions of "SELECT"
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| − | + | 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 |
| − | < | + | <div class=params>schema:scott</div> |
| − | < | + | The table <code>games</code> shows the year and the city hosting the Olympic Games. |
| − | < | + | <table border='1'> |
| − | <th> | + | <caption>games</caption> |
| − | <th> | + | <tr> <th>yr</th> <th>city</th> </tr> |
| − | </tr> | + | <tr> <td align='right'>2000</td> <td>Sydney</td> </tr> |
| − | <tr> | + | <tr> <td align='right'>2004</td> <td>Athens</td> </tr> |
| − | + | <tr> <td align='right'>2008</td> <td>Beijing</td> </tr> | |
| − | + | <tr> <td align='right'>2012</td> <td>London</td> </tr> | |
| − | <td align='right'> | + | |
| − | <td | + | |
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| − | </tr> | + | |
| − | <tr> | + | |
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| − | <td align='right'> | + | |
| − | <td | + | |
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| − | </tr> | + | |
| − | <tr> | + | |
| − | + | ||
| − | + | ||
| − | <td align='right'> | + | |
| − | <td | + | |
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| − | </tr> | + | |
| − | <tr> | + | |
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| − | <td align='right'> | + | |
| − | <td | + | |
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| − | </tr> | + | |
</table> | </table> | ||
| − | + | <div class=qu> | |
| − | + | The SELECT statement returns results from a <i>table</i>. | |
| − | + | In this example the table is <code>games</code> and the columns are | |
| − | <div class= | + | <code>yr</code> and <code>city</code>. |
| − | < | + | <div class=tidy> |
| − | + | DROP TABLE games; | |
| − | + | ||
| − | + | ||
| − | < | + | |
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| − | </ | + | |
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</div> | </div> | ||
| + | <div class=setup> | ||
| + | CREATE TABLE games(yr INT, city VARCHAR(20)); | ||
| + | INSERT INTO games(city,yr) VALUES ('ouroalpha',2000); | ||
| + | INSERT INTO games(city,yr) VALUES ('Athens',2004); | ||
| + | INSERT INTO games(city,yr) VALUES ('Beijing',2008); | ||
| + | INSERT INTO games(city,yr) VALUES ('London',2012); | ||
| + | </div> | ||
| + | <div class=def> | ||
| + | SELECT yr, city FROM games | ||
| + | </div> | ||
| + | </div> | ||
| + | |||
| + | ===See also:=== | ||
| + | *[http://sqlzoo.net/w/index.php/SELECT_from_BBC_Tutorial SELECT Tutorial] - practice using the SELECT command | ||
| + | *[[SELECT .. WHERE]] - the WHERE clause allows you to get some rows but not others | ||
Revision as of 12:19, 11 November 2012
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 |
|---|---|
| 2000 | Sydney |
| 2004 | Athens |
| 2008 | Beijing |
| 2012 | London |
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)); INSERT INTO games(city,yr) VALUES ('ouroalpha',2000); INSERT INTO games(city,yr) VALUES ('Athens',2004); INSERT INTO games(city,yr) VALUES ('Beijing',2008); INSERT INTO games(city,yr) VALUES ('London',2012);
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
