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shajimanjeri
Posting Yak Master
179 Posts |
 Posted - 2008-06-14 : 05:35:45
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| How can I write a trigger for the below issue,I have table named Subscribers with fields Name (varchar), MobileNumber (varchar), status (char). Here if I want to insert a record into this table then first I need to check whether this mobile number exist or not in this table. If it is not exist then this record should be insert and if it is exist then this record should not be insert in to this table.How can I do a trigger for this one?with regardsShaji |
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PeterNeo
Constraint Violating Yak Guru
357 Posts |
Posted - 2008-06-14 : 06:13:00
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| for this u can use SP rather than Trigger as mobileno is parametersome thing like this will do u r jobif not exists ( select 1 from tbl where mobileno = @mobileno )insert else return |
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mfemenel
Professor Frink
1421 Posts |
Posted - 2008-06-14 : 07:00:17
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| If this is something your doing frequently and the table is large, make sure you have some form of index on mobile number of your performance is going to be horrible.Mike"oh, that monkey is going to pay" |
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shajimanjeri
Posting Yak Master
179 Posts |
Posted - 2008-06-14 : 07:04:40
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| Can you give me a real example on this please? |
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shajimanjeri
Posting Yak Master
179 Posts |
Posted - 2008-06-14 : 07:11:35
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| or is there any way to avoid duplicate entry of mobile number in this table? |
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mfemenel
Professor Frink
1421 Posts |
Posted - 2008-06-14 : 07:43:49
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| If you want to absolutely prevent duplication you could make the mobile # the primary key or add a unique constraint to the field. If an attempt is made to insert a duplicate it will fail which will need to be trapped and handled.Mike"oh, that monkey is going to pay" |
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Trigger code