how to zero value accepted in table using foreign key

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SQL

select * form tbl_customer
column: id,name,price

select * from tbl_order

column:order_id,id,product_name

two table relationship foreign key..

but tbl_order how to accepted a 0 value from tbl_customer

Posted 10-Jun-15 3:22am

MohamedEliyas

Updated 10-Jun-15 3:34am

CHill60

v2

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CHill60 10-Jun-15 9:35am

It's still not clear what you are trying to do. Can you provide an example of the data in the tables (3 or 4 rows only) and what you are expecting to see after running the query

ZurdoDev 10-Jun-15 9:44am

The value in the foreign table has to match a value in the source table. You can't get around that, except for using NULL.

MohamedEliyas 11-Jun-15 2:26am

any example query using null and foreignkey

ZurdoDev 11-Jun-15 7:29am

Sure, insert NULL instead of a value.

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Peter Leow · Answer 1 · 2015-06-10T04:19:00

Your database design makes no sense.
1. Why is price in the tbl_customer table?
2. Why is product_name in the tbl_order table?
Re-look into the database design:
1. http://www.datanamic.com/support/lt-dez005-introduction-db-modeling.html[^]
2. http://www.studytonight.com/dbms/database-normalization.php[^]
Some example:

Table Name      Columns
tbl_customer    cust_id (primary key)
                cust_name 
tbl_product
                product_id (primary key)
                product_name
                price
tbl_order
                order_id (primary key)
                cust_id (foreign key to tbl_customer)
                product_id (foreign key to tbl_product)