A SELECT with INNER JOIN don’t works

Ramon Quintana

7y1.2k

Hi, i have a Query to extrac records with "NULL" values from two diferents tables, if i execute them by separate it works, but i execute them together with a INNER JOIN don´t extrac any records, some reason for that??

here the evidence:

Query 1:

Query 2:

JOIN QUERY:

Thanks...

9 Replies

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Jeeva Subburaj7y ago
Accepted answer
if you want only null values, you have exclude non null values by adding condition in join.

SELECT * FROM TBL_1
INNER JOIN TBL_2
ON ISNULL(TBL_1.Field1,' ') = ISNULL(TBL_2.Field1,' ')
OR (ISNULL(TBL_1.Field1,' ') = ' ' AND (ISNULL(TBL2_Field2,' ') = ' ')
+2
Ramon Quintana7y ago
It works with this way:

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Ramon Quintana7y ago
Hi Jeevanatham Subburaj

Sorry but i have no so good news from this, i was reviewing the data through results and i found records with NOT NULL values..why could be that?

here evidence:

thank for you help
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Ramon Quintana7y ago
Hi Jeevanatham Subburaj, no words but a big THANK YOU.. DONE!!!

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Jeeva Subburaj7y ago
if you want to update NULL records to some value, use the following syntax.

UPDATE table_name SET field_name = ' '
WHERE field_name IS NULL

also, I would recommend you to go through some SQL basics to understand the core concepts that would help you to write complex queries.
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Ramon Quintana7y ago
Hi,
Jeevanatham Subburaj,

that´s because as you notice in query 2 field "trans_type" has (NULL) value, and in Query 1 you can see field "trans_type" has ' ' values.

I try to update it with UPDATE sentence but don´t get any results

What could happens here?

Thanks
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Jeeva Subburaj7y ago
Your inner join both side should have isnull(field name, ' ') I see you put isnull(field name, 'NULL') that's wrong..
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Ramon Quintana7y ago
Hi,
Jeevanatham Subburaj,

I made changes in my JOIN Query but this time retuned values NOT NULL, I Need this same data but with NULL values.

Evidence:

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Jeeva Subburaj7y ago
use IsNull in inner join condition since first table has ' ' and second table has NULL.
inner join processoReporteSQL ON isnull(cuentas_maestro.trans_type,' ') = isnull(ProcessReportSQL.trans_type, ' ')
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A SELECT with INNER JOIN don’t works

Jeevanatham Subburaj,