Category "coalesce"

SQL Server - NULL vs blank in IF condition - ISNULL vs COALESCE

I am expecting ELSE part to be printed in this case. But it doesn't. It works if the input is blank ''. But for null, it fails. Even with ISNULL and COALESCE, i

Order of CAST() and COALESCE() matters in MariaDB

I have a strange problem: There is a price in a JSON column in a table and the following statements give different results while they should give the same thing

How can I apply a condition to multiple rows using SQL? CASE WHEN / PARTITION OVER

I am trying to create a column that shows Yes or No based on a set of conditions. If the conditions are met, then 'Yes' would apply to every row in the group (e

Why do MySQL 8 IF and IFNULL return a BLOB result when testing a variable with value NULL?

Note: I have moved the essence of this question to here having learned some of what is happening but still wanting to understand. (In essence, ISNULL and COALES

Arel - How to coalesce a field and a string literal in an Arel query?

I inherited a big, complicated Arel query that pulled from a number of tables. A new requirement says that if one of those tabels doesn't have a value for a par

How to concatenate columns in a Postgres SELECT?

I have two string columns a and b in a table foo. select a, b from foo returns values a and b. However, concatenation of a and b does not work. I tried : sel

combine rows in data frame containing NA to make complete row

I know this is a duplicate Q but I can't seem to find the post again Using the following data df <- data.frame(A=c(1,1,2,2),B=c(NA,2,NA,4),C=c(3,NA,NA,5),D