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POmysql three joins
 

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    <p>I have a problem with mysql</p> <p>I have 3 tables:</p> <pre><code>Deposit +-------------------+-------------+------+-----+ | Field | Type | Null | Key | +-------------------+-------------+------+-----+ | id | bigint(20) | NO | PRI | | status | int(2) | NO | | | depositDate | datetime | NO | MUL | | reversePayment_id | bigint(20) | YES | UNI | | claim_id | int(2) | NO | UNI | | payment_id | bigint(20) | YES | UNI | +-------------------+-------------+------+-----+ </code></pre> <p>Payment</p> <pre><code>+--------------------------+---------------+------+-----+ | Field | Type | Null | Key | +--------------------------+---------------+------+-----+ | id | int(10) | NO | PRI | | paymentDate | timestamp | NO | MUL | | pin | int(10) | NO | MUL | | balanceChange | decimal(15,2) | YES | | </code></pre> <p>Claim</p> <pre><code>+------------------------+--------------+------+-----+ | Field | Type | Null | Key | +------------------------+--------------+------+-----+ | id | int(11) | NO | PRI | | fullName | varchar(100) | NO | | | depositSum | blob | NO | | | ip | varchar(39) | NO | | | status | int(2) | NO | | +------------------------+--------------+------+-----+ </code></pre> <p>I try to select deposits (with claims) payment or reversePayment were between two dates, I perform this query with 3 joins:</p> <pre><code>EXPLAIN SELECT this_.id AS id60_3_, ..., fcpayment2_.id AS id59_0_, ..., reversepay3_.id AS id59_1_, ..., cl1_.id AS id61_2_, ... FROM Deposit this_ INNER JOIN Payment fcpayment2_ ON this_.payment_id = fcpayment2_.id LEFT OUTER JOIN Payment reversepay3_ ON this_.reversePayment_id = reversepay3_.id INNER JOIN Claim cl1_ ON this_.claim_id = cl1_.id WHERE ( ( fcpayment2_.paymentDate &gt;= '2010-08-04 21:00:00' AND fcpayment2_.paymentDate &lt;= '2010-08-05 08:01:00' ) OR ( reversepay3_.paymentDate &gt;= '2010-08-04 21:00:00' AND reversepay3_.paymentDate &lt;= '2010-08-05 08:01:00' ) ) ORDER BY this_.depositDate DESC </code></pre> <p>the result is</p> <pre><code>+----+-------------+--------------+--------+--------------------------------------------------------------------+----------+---------+-----------------------------------------+--------+---------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+--------------+--------+--------------------------------------------------------------------+----------+---------+-----------------------------------------+--------+---------------------------------+ | 1 | SIMPLE | cl1_ | ALL | PRIMARY | NULL | NULL | NULL | 426588 | Using temporary; Using filesort | | 1 | SIMPLE | this_ | eq_ref | claim_id,payment_id,FKDB5A0548511B6CDD,FKDB5A054867BA4108 | claim_id | 4 | portal.cl1_.id | 1 | | | 1 | SIMPLE | fcpayment2_ | eq_ref | PRIMARY,paymentDate,date | PRIMARY | 4 | portal.this_.payment_id | 1 | Using where | | 1 | SIMPLE | reversepay3_ | eq_ref | PRIMARY | PRIMARY | 4 | portal.this_.reversePayment_id | 1 | Using where | +----+-------------+--------------+--------+--------------------------------------------------------------------+----------+---------+-----------------------------------------+--------+---------------------------------+ </code></pre> <p>Why the first table in result is cl1_ and why mysql doesn't use key?</p>
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    1. USAnev
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      1. VTUpMod
    1. COJust something that caught my eye : your foreign keys are inconsistent. In Deposit, your claim_id field is int(2), in Claim your id field is int(11). Same goes for your payment ids. You should try to prevent this, and make sure they are of the same type...
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      1. USwimvds
 

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