Category Archives: Reference

Short references for personal… reference. Basically a howto for the tech-savvy.

Forcing an ARRAY() in postgres subqueries

Quick note to self, when making a complicated query, comparing to data in a subquery, the postgres query planner will sometimes decide to perform the entire outer query without the comparison, cache the results, and then run the inner query. Example: SELECT DISTINCT …FROM …INNER JOIN … ON …WHERE … AND … AND …id IN […]

TIKI-100 Documentation

Archiving some documentation for the Norwegian microcomputer TIKI-100 here, in case anyone needs it. I’ve sold mine, but Tommy Ovesen of Arctic Retro has graciously scanned the manuals I had for them. They’re here as well, for redundancy: User Manual – Instruksjonsbok TIKOS User/Technical Manual – TIKOS Bruker- og teknisk manual Software Catalog – Programvarekatalog […]

Allowing an empty JSON body, or no Content-Type, in a C# ASP.NET Core API

NOTE: In applications targeting net7.0+, Microsoft has fixed this issue, and you can set your Object to be default null (MyClass thingamagic= null), having it work as expected.Leaving the below hack in here for anyone stuck on net6 or below. — You may be here because you’re getting this: {“type”:”″,”title”:”Unsupported Media Type”,”status”:415,”traceId”:”00-0d785f3d1cb4fd71bc36ee25561e4b48-6bc5df1f0d070024-00″} Or this: {“type”:”″,”title”:”One […]

Moving columns in PowerQuery without naming every column

If you have pivoted data, you probably don’t want to name all the columns to move one, as a lot of them are going to contain dynamic data. The solution is to use the list of columns, manually moving the one you want into the desired position, as such: = Table.ReorderColumns(PreviousStepName, List.InsertRange(List.RemoveItems(Table.ColumnNames(PreviousStepName), {“ColumnToMove”}), 4, {“ColumnToMove”})) […]

Unpivoting two columns in PostgreSQL

We recently had a need to unpivot two columns with item id’s in them so they’d come out as a single column with distinct values. Some of the entries had <null> as the parent id, and null should not appear in the output. One could solve this with a simple UNION, but the view we […]

Recursive PostgreSQL user manager query for PowerBI path value, with loop handling

Recursive SQL queries. They’re hard to read, and even harder to wrap your head around. They’re handy when you have a self-referencing table (intermediates allowed, but complicates things) that somehow represents a tree, such as the management tree of a corporation, where each user has a manager_id that’s also a user_id in itself. There’s a […]

AWS RDS IAM Login pitfalls and checklist

So, you’re struggling with your IAM role login? psql: error: FATAL: password authentication failed for user “mydbuser”psql: error: FATAL: PAM authentication failed for user “mydbuser” This list is specifically for PostgreSQL, accessed by ECS containers and developers, but most of it would apply to any IAM compatible setup. First, check that you have allowed IAM […]