What is the help of joins? Where it will be use? Whats the importance of loops?
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What is the help of joins? Where it will be use? Whats the importance of loops?
[QUOTE=shanusk1;29485]What is the help of joins? Where it will be use? Whats the importance of loops?[/QUOTE]
[B]>>What is the help of joins?[/B]
Join is used to retrieve information from realted tables.
In other words it is used to combine columns from different tables.
[B]>>Where it will be use?[/B]
That depends upon the situation.
Equi join is useful when you are retreiving data from tables having common columns
Non Equi Join useful when tables do not have common columns
Outer Join gets rows returned by eui join + rows do not match from other tables.
Self join - Joining table to itself.
[B]>>Whats the importance of loops?[/B]
Repeats the same process number of times.