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What is aggregate function? Briefly describe it?
Aggregate functions are functions that take a collection of values as input and return a one value. SQL offers 5 built-in aggregate functions:
a) Average: avg
b) Minimum:min
c) Maximum: max
d) Total:sum
e) Count:count
Average: avg
Select avg (balance)
From account
Where branch-name='perryridge'
Count :count
Select branch-name,count(distinct customer-name)
From depositior,account
Where depositor.account-number=account.account-number
groupby branch-name
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can you create a database for me in oracle/sql
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Explain how the object classes are mapped to tables. Each object class maps to one or more than one tables in the database. The objects in the class may be partitioned horizont
The JOIN operation is applied on two relations. When we want to choose related tuples from two given relation join is used. The join operation need that both the joined relations m
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