How to prevent table creation without primary key in Postgres? – Postgresql
I would like to enforce a rule such that when people are creating table without primary key, it throws an error. Is it possible to be done from within pgdb?
Query the Latest Data Based On Condition in Multiple Columns and Concat Them – Mysql
I have a database like this employees I try to query the latest job and salary for every employees based on latest s_from_date and t_from_date and concat it to one column "Current Employees" I try to filter it with max(s_from_date)…
how do i join third table values into main join? – Mysql
in query here i have https://www.db-fiddle.com/f/32Kc3QisUEwmSM8EmULpgd/1 SELECT p.prank, d.dare FROM dares d INNER JOIN pranks p ON p.id = d.prank_id WHERE d.condo_id = 1; i have one condo with id 1 and it have unique connection to dares that has…
Joining table to itself with multiple join criteria logic – Mysql
I'm trying to understand the logic behind the syntax below. Based on the following question, table and syntax: Write a query that'll identify returning active users. A returning active user is a user that has made a second purchase within…
The query returns wrong result when i want to find who is the shortest player in a NBA Database – Mysql
I am working with a NBA script in MySQL and I have to find out who is the shortest player in database. I am using feet as measurement and after executing the query i found out that the player the…
select nested array details from Json stored as character type in postgresql
The tables in the query are not designed or controlled by me. Please don't tell me to change the table structure because it is outside my scope. using "PostgreSQL 11.16 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 7.3.1 20180712 (Red Hat…
SQL Consecutive Monthly Purchases – Mysql
I'm having great difficulty writing this query and cannot find any answers online which could be applied to my problem. I have a couple of tables which looks similar to the below with. Each purchase date corresponds with an item…
How to automatically delete empty rows in SQL? – Mysql
I have a SQL databases of users forms, and want to set up some routine or maybe even PHP that will automatically delete empty rows which looks like this: Column1=(Name=John Surname=Doe) | Column2=(Name=John Surname=) | Column3=(Name=John Surname=Doe) In this case…
Why does this query return values? – Mysql
I am starting to learn SQL and I had a question. I am running the following query: SELECT ProductName FROM Products WHERE ProductID =ALL ( SELECT ProductID FROM OrderDetails WHERE Quantity < 0 ) order by ProductID; Why does this…
Update json string column with proper json in Postgres SQL – Postgresql
I have a column which type is JSON but it contains JSON strings like this: "{"a":1,"b":2,"c":3}" I want to update the values in the column with proper JSON objects without the quotes and escapes like this: {"a":1,"b":2,"c":3} I've tried the…