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Re: Union and NULL
Posted by: Ramalingam Chelliah
Date: August 11, 2004 04:27AM

Hi ,
Today I found some user comment in ALTER TABLE Documentation Page....

Check this one out.. ( Third Comment )
Posted by Radhakrishnan Ayyappanaicker on April 13 2004 2:41am [Delete] [Edit]

while adding primary key constraint on null allowable integer column, mysql assigns default value 0 iff one NULL value exists on that column else alter table will fail with error "Duplicate entry '0' for key 1"


Note that he has mentioned something like "mysql assigns default value 0 iff one NULL value exists on a Column(Null allowable Integer) made as Primary Key...

Hope this is useful ....


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August 10, 2004 03:26AM
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August 11, 2004 04:20AM
Re: Union and NULL
August 11, 2004 04:27AM

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