Question : I have 3 tables, vendors, vendor_modelsand cameras. I am trying to get some values from db all of […]
Tag: join
Express union which is dependent on other results
Question : I would like to make a union of two tables that are actually in a hierarchical constellation. How […]
PostgreSQL join subquery can’t restrict query
Question : I’m working on a check-splitting project that splits out amount owed for an activity. Users can be a […]
Mysql query to get count result and group by
Question : I’ve got three tables with different records for users, User username | realname | date evn-az-3ju john 11/2012 […]
Use values from one column as column names and sum data from another table
Question : I’m going to do my best to describe this. So I have 3 tables as follows: project id […]
How to remove data from multiple tables with different foreign keys without using ON DELETE CASCADE?
Question : I have the following SELECT statement: SELECT * FROM “Users” u INNER JOIN “Calendars” c ON (u.”UserId” = […]
Optimizing multi-table left joins
Question : I have four tables which I am trying to join together. Table event +————+——————+——+—–+———+——-+ | Field | Type […]
Column name naming conventions and best practices
Question : I would like some expert opinion on best practices when it comes to column naming. The background is […]
Increasing join performance on very large table
Question : I have the following query in Postgres database SELECT (rel.”external-institute” || ‘#’ || rel.”external-institute-code”)::varchar(50) FROM public.”td_documents” d JOIN […]
Must an index cover all columns to be used in a merge? [closed]
Question : Closed. This question needs details or clarity. It is not currently accepting answers. Want to improve this question? […]