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Hongxin Technology & Trade Ltd. of Xiangtan City (abbr, HXTT)

HXTT DBF
Left Join Syntax
Ralph Mace
2008-11-13 06:29:42.0
My company has been experimenting with your JDBC DBF drivers; they seem to work quite well. But we are having a problem with the correct syntax for a left join operation.

The following query works correctly

SELECT I.FACID, I.REFNUM, I.PATNAME, I.DETAIL1, I.LOGAS, I.REPORTER, R.REPNAME, R.RADDRESS, R.RCITY
FROM INCIDENT AS I JOIN REPORTER AS R ON I.REPORTER = R.REPORTER

But, in some cases, rows from te INCIDENT table are omittted because there is
no matching row in the REPORTER table. If we change the query to read as follows:

SELECT I.FACID, I.REFNUM, I.PATNAME, I.DETAIL1, I.LOGAS, I.REPORTER, R.REPNAME, R.RADDRESS, R.RCITY
FROM INCIDENT AS I LEFT JOIN REPORTER AS R ON I.REPORTER = R.REPORTER

We get an empty ResultSet, even though we know that there are matching rows.

Is there a problem with the syntax we are using?

Re:Left Join Syntax
HXTT Support
2008-11-13 21:31:17.0
Your sql is correct. Failed to recur your issue. Please send us your dbf samples. BYW, if your INCIDENT contains only deleted rows, you will get an empty ResultSet.
Re:Re:Left Join Syntax
Ralph Mace
2008-11-14 03:37:38.0
Thanks for your answer. Unfortunately, the tables involved are much too
large and contain confidential information. We will recheck the INCIDENT table for
deleted rows.

Ralph Mace
Re:Re:Re:Left Join Syntax
HXTT Support
2008-11-14 23:02:17.0
You can try deletesAreVisible=true connection property.

BTW, the quickest way is to use
SELECT I.FACID, I.REFNUM, I.PATNAME, I.DETAIL1, I.LOGAS, I.REPORTER FROM INCIDENT
AS I

to see wheteher HXTT DBF can see those rows.

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