| some questions [message #79038] |
Tue, 16 April 2002 13:50  |
HAMID ALI
Messages: 1
Registered: April 2002
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Junior Member |
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Hello ,
Jhon, UK.
I have these problems/questions.
1. What is difference between constraints and triggers?
2. Tell me the syntex of the RR Date format.
3. What is the purpose of the Composite Primary key.
4. How Indes works?
5. Difference between functions and packeges?
6. Why we use Where Current Of clause in cursor?
Hope for quick answers.
Make understand in as easy as possible words.
go4surf@hotmail.com
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| Re: some questions [message #79045 is a reply to message #79038] |
Tue, 16 April 2002 23:59  |
N
Messages: 26
Registered: April 2002
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Junior Member |
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1. constraints. ie. must exist in table a, before it exists in table b. "Referential integrity"
2. Date format "DD-MON-RRRR"
3. Comp primary key. Two or more columns make up a composite key to reference a column in another table. Look up also "Foreign Key"
4. I assume you mean "index". Try and relate to the cocept of a book. You refer to the index in the back of a book to make it easier to find information in the book. Same applies to a dbase.
5. function is is/can be enclosed in a package. A package can be made up of procedures, functions, etc ...
6. Where current of. CAN be used to make data manipulation easier to execute, code and maintain.
related to cursors, ( cursor - a space/area opened in the dbase to execute a piece of code)
hope this helps, say if you need anything clarifed
bye.
n.
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