On Wednesday 22 September 2010, sivaji j.g wrote:
Hi,
I am using support module for my current projects. This module often runs UPDATE SQL statement and checks db_affected_rows() before issuing INSERT statements like
db_query("UPDATE {support_ticket} SET message_id = '%s', state = %d, priority = %d, client = %d, assigned = %d WHERE nid = %d", isset($node->message_id) ? $node->message_id : '', $node->state, $node->priority, $node->client, $node->assigned, $node->nid); if (!db_affected_rows()) { db_query("INSERT INTO {support_ticket} (nid, message_id, state, priority, client, assigned) VALUES(%d, '%s', %d, %d, %d, %d)", $node->nid, isset($node->message_id) ? $node->message_id : '', $node->state, $node->priority, $node->client, $node->assigned); }
Better to do a SELECT first to check if a record with the nid concerned exists, if it does do UPDATE, if not do INSERT. db_affected_rows() will only return > 0 if an update results in changed data. This assumes that nid needs to be unique in the support_ticket table.
I assume this is with an intention of avoiding duplicate records inserts. However in my case db_affected_rows() mostly returns 0 though a matching row is found in the table.
I guess it is because the values being updated is same as values already available in the row. As a result drupal throws user warning like.
user warning: Duplicate entry '292' for key 'PRIMARY' query: INSERT INTO support_ticket (nid, message_id, state, priority, client, assigned) VALUES(292, '', 1, 2, 7, 11) in /sites/all/modules/support/support.module on line 650.
I am planning to rewrite all the UPDATE query with SELECT COUNT(*) to fix this. Is there any other workaround available for this ?
I am using Drupal 6.19, PHP 5.3 and MySQL Server version: 5.1.41-3ubuntu12.6 (Ubuntu).
Thanks in advance.
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