A friend asked for this, so I thought it'd be helpful:All tables with no primary key:use INFORMATION_SCHEMA;select CONCAT(t.table_name,".",t.table_schema) as tbl,from TABLES AS t LEFT JOIN KEY_COLUMN_USAGE AS c ON (t.TABLE_NAME=c.TABLE_NAME AND c.CONSTRAINT_SCHEMA=t.TABLE_SCHEMA AND constraint_name='PRIMARY') WHERE t.table_schema!="information_schema" AND constraint_name IS NULL;All tables and their primary keys, if exist:use INFORMATION_SCHEMA