查询从两个表中选择

Question

i am having trouble with what seems quite a simple select query, i know there are lots of tutorials out there for this, but none seem to work for me, i keep getting the

Warning: mysql_fetch_assoc() expects parameter 1 to be resource, boolean given

Error

Here is the query causing it, basically i just want to select from 2 different tables

$trash_statement = "SELECT * FROM user_inbox, user_outbox WHERE user_inbox.receiver_user_id='$user_id' AND user_outbox.sender_user_id='$user_id' AND mail_deleted='1'";

Any ideas, where i am going wrong?

Thanks

Answer 1

mail_deleted is not associated with any table name! That causes Mysql to return an error and not a resource as expected by mysql_fetch_assoc() .

MySql Error: saying that the field name is not related to anything

#1052 - Column 'mail_deleted' in where clause is ambiguous

YOUR QUERY

$trash_statement = "
  SELECT * 
  FROM user_inbox, user_outbox 
  WHERE user_inbox.receiver_user_id='$user_id' 
  AND user_outbox.sender_user_id='$user_id' 
  AND yourTableName.mail_deleted='1'";

FIX THIS:

... yourTableName .mail_deleted...