Manual:MigrateComments.php

Details
migrateComments.php is a maint-scripts>Special:MyLanguage/Manual:Maintenance scripts|maintenance script that migrates comments from pre-1.30 columns to the 'comment' table.

$wgCommentTableSchemaMigrationStage needs to be set to  or   for the script to do the migration.

While migrating comments in a table, the script assumes any rows with the ID field non-zero have already been migrated. Also it assumes the new field name is the same as the old with '_id' appended. It blanks the old fields while migrating.

The script migrates the following columns:

The comments are finally stored in the column comment_text in the new comment table.

To improve performance during the run-time of this script, for the tables revision and image, a temporary table named revision_comment_temp and image_comment_temp is being created during the migration. These two tables will be merged with the tables revision and images again in the future.