Toby's Log page 21

MySQL: DELETE with sub-query on same table

in

I had an issue with a MySQL query containing a sub-query recently where it worked fine when done as a SELECT query, but gave an error when switching it to a DELETE query. The error given was something like ‘You can’t specify target table “items” for update in FROM clause’. The sub-query was referencing the same table as the main query, which apparently can’t be done directly in MySQL because the table will be modified during deletion. But there is a sort of a hack I found in this StackOverflow answer, among others, to force it to create a temp table and allow it to work.

Continue reading post "MySQL: DELETE with sub-query on same table"

Swap file for composer out of memory problems

in

PHP’s defacto package manager, composer, has long required large amounts of memory to do updates for larger projects, often more than servers or virtual machines have. The script will die with an out of memory error, or more recently, the simple message “Killed”, and do no work in these situations. The normal procedure is to develop locally, deploy local lock file (composer.lock) to the server, and run composer install instead of update. But I’ve recently moved to doing most of my development in VMs, so I have had to work around this problem to get things installed or updated. A swap file is the solution for Linux machines provided in the official docs and expanded in a StackOverflow answer.

Continue reading post "Swap file for composer out of memory problems"