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Access scalar query allows you to do in one SQL statement what you are used to doing in two or more queries. This function allows retrieval of single values from a table, usually aggregate functions, from within the from clause.Get individual values while at the same time getting max, min, avg, etc values from the same source without having to use the Group By clause... this greatly simplifies query design. Here's the setup for our scalar query example:
Our goal is the retrieve SSN, Pay_Rate, Max Pay_Rate, Min Pay_Rate, and calculate each employees' percent of maximum pay rate.
See the following SQL statement:
Don't bother trying to create this in the design grid. You must get into SQL view. The key point of the query is:
[select max(pay_rate) as Max_R from m_emp_pay]. as Q_Max There are two aliases in this subquery - Max_R for the field and Q_Max for the source name. See how these aliases are immediately used in the Select clause of the query. No group by required!! Therefore you get the individual pay rates for employees while, at the same time, retrieving min, max, and most importantly the percent of max.
See the results of the query below:
The main restriction with scalar SQL statement is that the function can only return a single value, although you can have multiple subquerys in one main query.
