Pitney Bowes MapInfo Professional - Manual (Page 252)

SALES MONTH SALES_REP
1400 June Cathy
600 June Julie
1200 July John
700 July Cathy
1000 July Julie
MapInfo Professional could also compute the total sales for each representative by specifying in the
SQL Select dialog box:
• Select Columns: SALES_REP, sum(SALES)
• Group by Columns: SALES_REP
sum(SALES) SALES_REP
3300 John
3000 Cathy
2700 Julie
or MapInfo Professional could compute the average sales for each representative:
• Select Columns: SALES_REP, avg(SALES)
• Group by Columns: SALES_REP
avg(SALES) SALES_REP
1100 John
1000 Cathy
900 Julie
or MapInfo Professional could compute the total sales for each month:
• Select Columns: MONTH, sum(SALES)
• Group by Columns: MONTH
sum(SALES) MONTH
3200 May
2900 June
2900 July
MapInfo Professional has six aggregate functions:
• Count(*): counts the number of records in a group. It takes * as its argument because it applies to the
record as a whole, and not to any particular field in the record.
• Sum (expression): calculates the sum of the values in <expression> for all group records.
MapInfo Professional 12.5 252
Querying Your Data in MapInfo Professional