sql-delete

How to delete rows from multiple tables in one query (with left join). The query: DELETE `deadline`, `job` FROM `deadline` LEFT JOIN `job` .... So, I try it like this: DB::table('deadline', 'job') ->leftJoin('job', 'deadline.id', '=', 'job.deadline_id') ->where('deadline.id', $id) ->delete(); Seems that Laravel doesn't support delete from multiple tables with left join. Is there a supported way or workaround? It seems that my way is not possible. So, I did it like this. $q = 'DELETE deadline, job FROM deadline LEFT JOIN job ...where deadline.id = ?'; $status = \DB::delete($q, array($id));

Consider 2 or more tables: users (id, firstname, lastname) orders (orderid, userid, orderdate, total) I wish to delete all users and their orders that match first name ' Sam '. In mysql, I usually do left join. In this example userid is unknown to us. What is the correct format of the query? Juan Carlos Oropeza http://www.postgresql.org/docs/current/static/sql-delete.html DELETE FROM orders o USING users u WHERE o.userid = u.id and u.firstname = 'Sam'; DELETE FROM users u WHERE u.firstname = 'Sam'; You can also create the table with ON delete cascade http://www.postgresql.org/docs/current

What limit should be placed on the number of rows to delete in a SQL statement? We need to delete from 1 to several hundred thousand rows and need to apply some sort of best practise limit in order to not absolutely kill the SQL server or fill up the logs every time we empty a waste-basket. This question is not specific to any type of database. That's a very very broad question that basically boils down to "it depends". The factors that influence it include: What is your level of concurrency? A delete statement places an exclusive lock on affected rows. Depending on the databse engine, deleted

I am trying to delete a few records but am getting the following error: Cannot delete or update a parent row: a foreign key constraint fails The thing is, the foreign key constraint is failing for only 1 or 2 of my 100 records I wish to delete. I wish to write a query which deletes these 98-99 records, skipping the 1 or 2 which failed , which I can later manually inspect and delete/modify. Not stopping because of some single problematic record, but continuing with the others, ignoring that. Is there a neat way to do this ? You have to LEFT JOIN the referencing table and add a condition saying

I have outputted the results of a MySQL table to an HTML table. In the last column, I want to add a delete option which calls another form and deletes the user. I can't seem to get it to work though. This is my code for the results page: <?php $contacts = mysql_query(" SELECT * FROM contacts ORDER BY ID ASC") or die( mysql_error() ); // If results if( mysql_num_rows( $contacts ) > 0 ) ?> <table id="contact-list"> <thead> <tr> <th>Name</th> <th>Email</th> <th>Telephone</th> <th>Address</th> <th>Delete</th> </tr> </thead> <tbody> <?php while( $contact = mysql_fetch_array( $contacts ) ) : ?> <tr>

If list LL: LL = ['foo', bar', 'noo', 'boo',] is in a MySQL table, test in column ID with other ID's. I could use the following to delete all rows with ID's in LL: csr.execute("""DELETE FROM test.test WHERE ID = "Foo"; """) csr.execute("""DELETE FROM test.test WHERE ID = "bar"; """) csr.execute("""DELETE FROM test.test WHERE ID = "noo"; """) csr.execute("""DELETE FROM test.test WHERE ID = "boo"; """) How could I do it programatically? You can do it with a single query: id_list = ['abc', 'def', 'ghi'] query_string = "delete from test where id in (%s)" % ','.join(['?'] * len(id_list)) cursor