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MySQL Query problem on join

Posted on 2009-04-02
Last Modified: 2013-12-12
I have a simple query running against MySQL through PHP.  I want to insert into a table all values that are in another table but not in that table.  This is the query I have:

INSERT Into DataNew (CollectorCode,CollectGross)
SELECT DISTINCT DataHistory.CollectorCode, 0
FROM DataHistory
LEFT OUTER JOIN DataNew ON DataNew.CollectorCode = DataHistory.CollectorCode
WHERE DataHistory.CodeType =1
AND DataHistory.CollectorCode NOT LIKE '%-b'
AND DataNew.CollectorCode IS NULL

The trouble is that the select query returns 602 rows whether I fileter by the DataNew.CollectorCode is Null or not.  How can I go about insertings into DataNew all Collectorcodes from DataHistory which are not already present?
Question by:GeoffSutton
  • 2
LVL 22

Expert Comment

ID: 24052807

I would do like this (if CollectorCode is unique)

INSERT Into DataNew (CollectorCode,CollectGross)
SELECT DISTINCT dh.CollectorCode, 0
FROM DataHistory dh
WHERE NOT EXISTS (SELECT 1 FROM DataNew dn WHERE dn.CollectorCode = dh.CollectorCode)

LVL 10

Author Comment

ID: 24053143
Unfortunately that does not work.  You query:
SELECT DISTINCT dh.CollectorCode, 0
FROM DataHistory dh
WHERE NOT EXISTS (SELECT 1 FROM DataNew dn WHERE dn.CollectorCode = dh.CollectorCode) AND
Returns the exact same results as
SELECT DISTINCT dh.CollectorCode, 0
FROM DataHistory dh
WHERE dh.CodeType=1

 They both show 602 rows, and datanew has 149 distinct codes entered.  I was reasonably sure that the SQL and the logic were good.  But being unfamiliar with MySQL I am wondering if the comparisons pay attention to potential trailing spaces and hidden characters?  I know that the collation is case insensitive.
Thanks for the quick response.  Hopefully we can resolve this right away.
LVL 22

Accepted Solution

pivar earned 500 total points
ID: 24053248
Just so I understand, CollectorCode is unique?

Can you show us the tabledefinition and some sampledata?

If you would like to trim the CollectorCode try

SELECT DISTINCT dh.CollectorCode, 0
FROM DataHistory dh
WHERE NOT EXISTS (SELECT 1 FROM DataNew dn WHERE TRIM(dn.CollectorCode)=TRIM(dh.CollectorCode)) AND

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