Lost connection to MySQL server during query

Hi Guys

If I execute this type of select command I get following error

select Distinct B.cdlabel, cdlabelText from cdlabel A ,entrycheck B, markingqc C where B.ImageId=C.ImageId and A.cdlabel = B.cdlabel and markingqc =2 and (B.BatchidName<>0 or B.BatchidLegal<>0) and ( KeyQc=0 )and ( Key1=6) and ( Key2=6) and counterN =1 and markflag = 0 AND IMAGEORDER =1 and utility <>1 order by cdlabelText

Error Code : 2013
Lost connection to MySQL server during query
(0 ms taken)

Even this error occurs while executing in Qury browser.

I created index also.

If the DB contains minimum records the result is displayed

If DB contains more number of records “Lost connection to MySQL server during query” error displayed.

Why this error occurs and what is the solution for it?

Thanks