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From:<lakshmi.narasimharao Date:March 30 2005 3:47am
Subject:Regarding NULL and '' (null string) treatment in MYSQL
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Hi,

    MySQL treats NULL, '' (empty string) as different.

    I mean when I select from/insert into a table, its behaviour is
different. 

   Select * from table1 where name=''; 

   is different from

   Select * from table1 where name=NULL;  

   Similarly

   Insert into table1(name) values('')  is different from

   Insert into table1(name) values(NULL) 

   Please suggest me here, how to overcome this '' (null string)
problem.

 Scenario:

 I have two tables, one is parent and one is child.

 Child is referencing 3 fields in parent table.

Parent table records are empty. Now I am trying to insert into the child
table with  '' (null string) values into these 3 fields (which are
referencing to the parent table).  Actually insert into the child table
in this scenario should be successful, but I am not able to make it
success because of the problem described above ( Treatment of NULL, ''
are different).

Note: If the parent is not having any records, we can insert into the
child. BCS, in this case referential integrity won't work.
  
Ps: In oracle, it is not the case it treats NULL,'' as same.


Please suggest me how to proceed here.


Thanks,
Narasimha



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Thread
Regarding NULL and '' (null string) treatment in MYSQLlakshmi.narasimharao30 Mar
  • Re: Regarding NULL and '' (null string) treatment in MYSQLPeter Brawley30 Mar
    • Re: Regarding NULL and '' (null string) treatment in MYSQLShankar Unni30 Mar