Clever Geek Handbook

Select count (*) from many tables

Dear friends. I have a requirement to get score (*) from one table with different criteria. I am using hibernate with spring. I am using below query for this.

"select  " +
            "(select count(*)  from enquiry  where business_id="+busid+")  AS allEnqCount,"+
    "(select count(*)  from enquiry where status='"+Constants.ENQ_FALLOWUP+"' and us.business_id="+busid+")  AS followupCount," +
    "(select count(*)  from enquiry where status='"+Constants.ENQ_SITE_VISIT+"'and us.business_id="+busid+")  AS siteVisitCount ," +
    "(select count(*)  from enquiry where status='"+Constants.ENQ_CUST_VISIT+"'and us.business_id="+busid+")  AS customerVisitCount," +
    "(select count(*)  from enquiry where status='"+Constants.ENQ_OFFICE_VISIT+"'and us.business_id="+busid+")  AS officevisitCount,"+
    "(select count(*)  from enquiry where status='"+Constants.ENQ_PENDING+"'and us.business_id="+busid+")  AS pending";

But it takes some considerable time. Can you tell me that I can do this in minimal time and in one select clause.

Thanks in advance.

+3


source to share


2 answers


Use group by

:

Something like:



select 
      status,
      count(*) 
from enquiry 
where business_id = @busid 
group by status
+1


source


use CASE 

SELECT  SUM(CASE WHEN business_id = 'busid' THEN 1 END) allEnqCount,
        SUM(CASE WHEN status = 'ENQ_FALLOWUP' AND us.business_id = 'busid' THEN 1 END) followupCount,
        SUM(CASE WHEN status = 'ENQ_SITE_VISIT' AND us.business_id = 'busid' THEN 1 END) siteVisitCount,
        SUM(CASE WHEN status = 'ENQ_CUST_VISIT' AND us.business_id = 'busid' THEN 1 END) customerVisitCount,
        SUM(CASE WHEN status = 'ENQ_OFFICE_VISIT' AND us.business_id = 'busid' THEN 1 END) officevisitCount,
        SUM(CASE WHEN status = 'ENQ_PENDING' AND us.business_id = 'busid' THEN 1 END) pending
FROM    enquiry


just change the values ​​to suit your needs.

+2


source






More articles:


All Articles