Question

I have tables

Tasks- id,name

then i have

userTasks id , task_id , user_id

and

User - id , name

Suppose i have 10 tasks in task table and out of those i have 3 tasks in userTask table

I want query like this

Select task.id , task.name , STATUS (if(presentInUserTasks),1,0) FROM whatever

the STATUS word should 1 if that task id is present in usertasks table for that userid otherwise it should be 0

So that i am able to find which of those tasks are alreadu in userTask table

Answer 1

You’re looking for the EXISTS keyword:

SELECT tasks.id, tasks.name, 
    IF(EXISTS(SELECT id 
              FROM userTasks 
              WHERE userTasks.task_id = tasks.id 
              AND userTasks.user_id = @that_user_id)
       ,1,0) AS STATUS
FROM tasks