how can select from table use in operator with array

Question

I have 2 table - users and posts. I get users list with next sql request :

$sql = "SELECT user_id FROM users WHERE some_param = 1";
$result = mysql_query($sql);

$result - Array.

After how I can get element from posts with $result?

$sql2 = "SELECT * FROM posts where user_id in ($result)";
$result2 = mysql_query($sql2);

But don't work it, please help .

Pupil · Accepted Answer · 2014-10-30 06:45:08Z

1

Use sub-queries to avoid running queries for multiple times.

Through this you can get expected data in one go.

$sql2 = "SELECT * FROM posts where user_id in (
SELECT user_id FROM users WHERE some_param = 1
)";

answered Oct 30, 2014 at 6:45

Pupil

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Comments

geoandri · Accepted Answer · 2014-10-30 06:46:52Z

1

You can also use a single query for this purpose by joining the tables

 $sql = "SELECT * FROM posts inner join users on users.user_id = posts.user_id  
        WHERE users.some_param = 1";

answered Oct 30, 2014 at 6:46

geoandri

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GautamD31 · Accepted Answer · 2014-10-30 06:44:15Z

0

$sql2 = "SELECT * FROM posts 
         WHERE user_id IN (". implode(',',$result) .")";

Even you directly write the sub query like

$sql2 = "SELECT * FROM posts 
         WHERE user_id IN (SELECT user_id FROM users WHERE some_param = 1)";

Also so many result in this

answered Oct 30, 2014 at 6:44

GautamD31

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