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Tag: sql

How to select size of json array in postgres?

I’ve been fighting this for a long time, but I am not able to construct a query, which would select (and preferably also order by) a count of items in an array. I do have table data like this: And what did I try… also But it sais I’ve tried a lot of different formats but coming from the MS

Delete all duplicates except first one mysql

I have a table with a column serial_number that is repeated a few times. How would I delete the entire row except the first duplicate? By the following, I can select all the duplicates. But can’t delete. SELECT serial_number, COUNT(*) FROM trademark_merge GROUP BY serial_number HAVING COUNT(*) > 1 An…

Many rows as a result of SELECT SQL

The table consists of the Record and Record author fields. There is an employee table with the Employee and His manager fields. It is necessary to read records from the first table that belong to a specific manager or his employees. I tried like this: Issued: ORA-01427: single row subquery returns more than o…

How to add to INSERT INTO PRIMARY KEY AND FOREIGN KEY

So i have two tables: locations and employees i want locations_id to be the same in employees.locations_id, I am trying to make it all in one statement the erros is this You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near &#8216…

Find Gaps in a single date column SQL Server

Good Day everyone, I need your help. I am trying to detect gaps in a single column of the type Date or DateTime in SQL Server. Say we have a list of schools and each school has many records and there is a field of uploadDate. So something like that: My outcome would be something like that: Thank you all.