Question

I have one image table and image view status table.

In each click of image I am tracking image view time. status. date time.. So in image view status table have more than one entry for one image.

I need to check whether one user already viewed one image or not.

So I write one query like this..

select A.title, if(B.view_status='completed','completed','notviewed') from images A left join imgstatus_view B on (A.imgId=B.ImgId and A.fileId=B.fileID) Where userId=1 and imgId=121

If I view one image three times its fetching 3 records. I need only one record to check whether user viewed the image or not.

So with out using DISTINCT or GROUP BY How can I fetch unique row of data.

Please help me.

Answer 1

you can use ORDER BY and LIMIT clause. to get most recent record you can use below query

select A.title, if(B.view_status='completed','completed','notviewed') from images A left join imgstatus_view B on (A.imgId=B.ImgId and A.fileId=B.fileID) Where userId=1 and imgId=121 ORDER BY datetimefield DESC LIMIT 0,1

to get old record

select A.title, if(B.view_status='completed','completed','notviewed') from images A left join imgstatus_view B on (A.imgId=B.ImgId and A.fileId=B.fileID) Where userId=1 and imgId=121 ORDER BY datetimefield LIMIT 0,1

if you dont have datetime field remove ORDER BY clause which will give most recent modified record