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plurals

PO
primarykey
Id
15253291
data
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0
AnswerCount
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ClosedDate
CommentCount
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CreationDate
2013-03-06T16:51:48.690
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2016-06-27T16:23:30.223
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2016-06-27T16:23:30.223
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224693
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224693
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12207045
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2
Score
7
ViewCount
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LastEditorDisplayName
text
Body
I don't know your queries, but seems like you're inserting row into child table, and then doing an update of row in parent table. If that's true, you've hit this issue in MySQL: <a href="http://bugs.mysql.com/bug.php?id=48652" rel="noreferrer">http://bugs.mysql.com/bug.php?id=48652</a> <blockquote> If a FOREIGN KEY constraint is defined on a table, any insert, update, or delete that requires the constraint condition to be checked sets shared record-level locks on the records that it looks at to check the constraint. InnoDB also sets these locks in the case where the constraint fails. On a single record of the first table you have: <ol> <li>S lock from transaction 1 set, </li> <li>S lock from transaction 2 set, </li> <li>X lock from transaction 1 requested, blocked by S lock from transaction 2, </li> <li>X lock from transaction 2 requested, blocked by S lock from transaction 1</li> </ol> </blockquote> Possible solution is to first update parent table, then insert row into child table. Suppose we need to increment some counter upon child row insertion, then queries would be: <pre><code>UPDATE <parent row> SET count = count + 1; INSERT <child row>; /* if the INSERT fails, roll back the trx */ </code></pre> If you want to update parent row only after inserting child row, you can use <code>FOR UPDATE</code> statement to set a lock on parent row: <pre><code>SELECT <parent row> FOR UPDATE; INSERT <child row>; /* if the INSERT fails, roll back the trx */ UPDATE <parent row> SET count = count + 1; </code></pre>
Tags
Title
singulars
PostAcceptedAnswerId
1. This table or related slice is empty.
PostParentId
1. POreproduce such deadlock in mysql
 singulars
 PostTypePostTypeId
 PTQuestion
PostTypePostTypeId
1. PTAnswer
UserLastEditorUserId
1. USIvan Virabyan
UserOwnerUserId
1. USIvan Virabyan
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. This table or related slice is empty.
VotesPostIdCreationDate
1. This table or related slice is empty.
CommentsPostId
1. This table or related slice is empty.

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