query SQL

[manjava]

hello,
i want to do this query

$sql = "SELECT * FROM `departement_2`,departement_5,departement_8,departement_12,departement_33,departement_15";
 

Does anyone have any ideas on what I should do? thanks.

[Rabbit]

You can certainly run that SQL. It's syntactically correct although I have no idea why you would want to have so many cartesian joins. It's going to eat up a lot of resources. But there's nothing in the syntax to prevent you from running that SQL.

[Atli]

The names of those tables suggest a fairly big problem with your design. Whenever you start putting actual data into the structure of the database, that should be a huge red flag. - In your case, you have "department_N", where N is a number that I'm guessing represents an ID for the department who's data it stores?

Generally you would put that data into a table, rather than create multiple tables wit the data in the table name. So instead of doing something like this:

department_1
+----+------------+----------+
| id | date       | whatever |
+----+------------+----------+
|  1 | 2013-01-01 |      ... |
|  2 | 2013-02-01 |      ... |
|  3 | 2013-03-01 |      ... |
+----+------------+----------+
 
department_2
+----+------------+----------+
| id | date       | whatever |
+----+------------+----------+
|  1 | 2013-01-01 |      ... |
|  2 | 2013-02-01 |      ... |
|  3 | 2013-03-01 |      ... |
+----+------------+----------+
 

You should be doing this:

department
+----+------------+----------+--------+
| id | date       | whatever | number |
+----+------------+----------+--------+
|  1 | 2013-01-01 |      ... |      1 |
|  2 | 2013-02-01 |      ... |      1 |
|  3 | 2013-03-01 |      ... |      1 |
|  4 | 2013-01-01 |      ... |      2 |
|  5 | 2013-02-01 |      ... |      2 |
|  6 | 2013-03-01 |      ... |      2 |
+----+------------+----------+--------+
 

The number there represents the department number the row belongs to.

This makes the data a LOT easier to work with, and makes it possible to add as many departments as is needed without having to keep creating new tables.