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akpaga
Constraint Violating Yak Guru
331 Posts |
 Posted - 2010-05-20 : 13:38:53
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| i have problem with my customer table .. . some times the same customer has multiple customer numbersso the customer_nbr field is actually a varchar(max) fieldso when a customer having multiple customer nbrs trie to insert a record in the following way say customer john can have0123,0234 john 1(opts in) ,04/22/2010say he comes again the next time and opts in just the customer nbr- 0234new record0234 ,john ,1(opts in),04/27/2010first time -0123, 0234second time -0123 they are not same programmatically how to check for this since the record should not be inserted saying you already opted in for this customer number but its not doing so...how can i do a check for these kind of situations.. thank you |
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lazerath
Constraint Violating Yak Guru
343 Posts |
Posted - 2010-05-20 : 14:21:00
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| This design does not conform to normalization rules. If you are building a transactional system, you should strive to reach the 3rd normal form.I recommend you read up on database normalization:http://en.wikipedia.org/wiki/Database_normalization |
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akpaga
Constraint Violating Yak Guru
331 Posts |
Posted - 2010-05-20 : 15:49:50
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quote:
Originally posted by lazerath
This design does not conform to normalization rules. If you are building a transactional system, you should strive to reach the 3rd normal form.I recommend you read up on database normalization:http://en.wikipedia.org/wiki/Database_normalization
Thanks for the response lazerath but the database has been designed already that way....can i use that design to compare customer numbers...thanks in advance |
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lazerath
Constraint Violating Yak Guru
343 Posts |
Posted - 2010-05-20 : 18:02:11
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| Ok, then you will need to parse that field with a function like ParseValues:http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=104485It should be noted that there is a big performance cost to doing this every time you want to insert a record because you'll need to parse every row to find if it already exists.A decent design would mitigate this cost. |
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check a string as integer