SQL Server Performance Forum – Threads Archive

Quickly determine existence of a record

Hello, I need to repeatedly determine the existence of a record that has a list of values: client = 1, service date = 1/1/05, etc. I am checking for duplicates based on certain columns. I am using select count(*) from table where client = 1, etc. to get my answers. Are there other ways to accomplish this? Any suggestions are appreciated. Thanks!

---

Not sure I fully follow. Are you sayin you are looking for a row that contains multiple columns with a speciifc entry your are concerned with or rows with any of the conditions met? What are you wantin to do with these once found?

---

may be you try this..
select count (*) as frq from table where client = 1 and service date =(….) group by client, service date this should give you a number which you can use for your needs.

---

If you want to know the duplicate values for the particular column, then use this select column from table group by column having count(*)>1
Madhivanan Failing to plan is Planning to fail

---

U can use if exists as well
Check this
http://www.sql-server-performance.com/forum/topic.asp?TOPIC_ID=8219

---

Hi SpeedyZ,
What i have understood is that u want to check whether a record with certain column values is there in the table or not then i feel u dont need to check count(*). U can try this. set nocount on
select client from table where client=1 and servicedate=’1/1/2005′
if @@rowcount>0 then do something
else do other things.
set nocount off

---

My favourite for listing duplicates is to use a derived table. Figure out your primary key – all the columns that will determine that a row is a duplicate eg, cola, colb, colc If table is called tableA then to list all duplicates you do: select * from
tableA inner join
(
select cola, colb, colc, count(*) dupcount
from tableA
group by cola, colb, colc
having count(*) > 1
) dups
on tableA.cola = dups.cola and tableA.colb = dups.colb and tableA.colc = dups.colc Dave Small Businesses
www.matiogi.com

---

If you want to check for existence then:
if exist(select * from table where …)
If you want to check for dups see answers above.

---

]]>