Quelle est la bonne requête ?

Bonsoir,

Je sature... quelle est la requête correcte parmi les trois suivantes ?

Code:

1
2
3
4
5
6
7
8
9
SELECT 
	table1.champ1 AS alias1,
	table2.champ2 AS alias2
FROM 
	table1 AS t1,
	table2 AS t2
WHERE 
	table1.champ1 = '$variable1' /* <- */
	table2.champ2 = '$variable2' /* <- */

Code:

1
2
3
4
5
6
7
8
9
SELECT 
	table1.champ1 AS alias1,
	table2.champ2 AS alias2
FROM 
	table1 AS t1,
	table2 AS t2
WHERE 
	alias1 = '$variable1' /* <- */
	alias2 = '$variable2' /* <- */

Code:

1
2
3
4
5
6
7
8
9
SELECT 
	table1.champ1 AS alias1,
	table2.champ2 AS alias2
FROM 
	table1 AS t1,
	table2 AS t2
WHERE 
	t1.champ1 = '$variable1' /* <- */
	t2.champ2 = '$variable2' /* <- */

Merci !