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plurals

PO
primarykey
Id
9837237
data
AcceptedAnswerId
0
AnswerCount
0
ClosedDate
CommentCount
0
CommunityOwnedDate
CreationDate
2012-03-23T10:03:02.660
FavoriteCount
0
LastActivityDate
2012-03-23T10:10:14.837
LastEditDate
2012-03-23T10:10:14.837
LastEditorUserId
4833
OwnerUserId
4833
ParentId
9837025
PostTypeId
2
Score
1
ViewCount
0
LastEditorDisplayName
text
Body
If you <a href="https://dev.mysql.com/doc/refman/5.0/en/create-index.html" rel="nofollow">create a <code>unique</code> index</a> for the column Username an insert with the same value for Username as an other record already in the table will cause a specfic error code. Your script can simply try to insert the new record and handle the specific error code, something like <pre><code>define('ER_DUP_KEY', 1022); // pre-condition: $user, $passwd, $boss have been prepared for usage within an sql statement $query = sprintf(" INSERT INTO tbluser (`Username`, `Password`, `BossID`) VALUES ('%s', '%s', '%s') ", $user, $passwd, $boss); if ( !mysql_query($query) ) { switch(mysql_errno()) { case ER_DUP_KEY: // handle duplicate user name break; default: // handle other errors } } </code></pre> If you would use two queries (SELECT+INSERT) you had to handle <a href="https://en.wikipedia.org/wiki/Race_condition#Computing" rel="nofollow">race conditions</a>, e.g. by locking the table. <hr> edit: I missed the implicit join <code>FROM tbluser, tblfile</code>. In that case you might be interested in <a href="https://dev.mysql.com/doc/refman/5.0/en/insert-on-duplicate.html" rel="nofollow">INSERT ... ON DUPLICATE KEY UPDATE</a>, esp. the <blockquote>If a table contains an AUTO_INCREMENT column and INSERT ... UPDATE inserts a row, the LAST_INSERT_ID() function returns the AUTO_INCREMENT value. If the statement updates a row instead, LAST_INSERT_ID() is not meaningful. However, you can work around this by using LAST_INSERT_ID(expr). Suppose that id is the AUTO_INCREMENT column. To make LAST_INSERT_ID() meaningful for updates, insert rows as follows: </blockquote> part. I.e.: <ul> <li>create a unique index for Username</li> <li>do the <code>INSERT INTO tbluser</code> query with an ON DUPLICATE KEY UPDATE clause using LAST_INSERT_ID(expr)</li> <li>fetch the insert id, see <a href="http://docs.php.net/function.mysql-insert-id" rel="nofollow">http://docs.php.net/function.mysql-insert-id</a></li> <li>do the second insert using the insert_id from the previsous query</li> </ul>
Tags
Title
singulars
PostAcceptedAnswerId
1. This table or related slice is empty.
PostParentId
1. POPHP User already exist check
 singulars
 PostTypePostTypeId
 PTQuestion
PostTypePostTypeId
1. PTAnswer
UserLastEditorUserId
1. USVolkerK
UserOwnerUserId
1. USVolkerK
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. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
CommentsPostId
1. This table or related slice is empty.

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