根据 CASE 语句执行 SELECT

Question

I am trying to execute a select statement depending on the CASE

SELECT CASE WHEN TO_CHAR(today, "%a") = 'Mon' 
THEN (SELECT COUNT(*) FROM  jobs WHERE datein > today-2) 
ELSE (SELECT COUNT(*) FROM  jobs WHERE datein = today) 
END CASE;

As a result I would expect if the day is 'Mon' (monday) then execute the Select from (monday - 2 days) and bring all the columns/rows not just 1 COUNT , ELSE execute the select for the current day.

In case the day is monday the result should be

id | jobs | date
1  |12,500| 12-7-2019
2  |10,800| 12-8-2019

In case the day is different from monday should be the same but for today's data

id | jobs | date
3  |35,000| 12-9-2019

If this is not possible is there any other method?(considering my limited access)

Database server: INFORMIX 12.1 I can read only the database using Toad for Data Analysts or IBM Data Studio.

Answer 1

Without a schema and data sample are hard to know exactly what you want, but if we assume that you want to get all rows from the table jobs depending on date, you can execute this query

SELECT jobs.*
  FROM jobs
 WHERE jobs.datein >=  CASE
                         WHEN WEEKDAY(TODAY) = 1 THEN TODAY-2
                         ELSE TODAY
                       END

I don't have the tools you mention, but this query run ok on Informix 12.10 and 14.10 from dbaccess.