A SELECT with INNER JOIN don’t works

Question

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...

Jeeva Subburaj · 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,' ') = ' ' )

Ramon Quintana · Answer

It works with this way:

Ramon Quintana · Answer

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

Ramon Quintana · Answer

Hi Jeevanatham Subburaj, no words but a big THANK YOU.. DONE!!!

Jeeva Subburaj · Answer

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.

Ramon Quintana · Answer

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

Jeeva Subburaj · Answer

Your inner join both side should have isnull(field name, ' ') I see you put isnull(field name, 'NULL') that's wrong..

Ramon Quintana · Answer

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:

Jeeva Subburaj · Answer

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, ' ' )