Expressions

Overview

An expression is a combination of one or more values, operators and SQL functions that evaluate to a value. You can also use them to query the database for a specific set of data. Expressions can be used on forms with Query control and in scripting with $Database methods.

Remarks

Expressions can consist of multiple SQL functions. The following functions are available;

Value	Description
Count	Count of row values.
CountDistinct	Count of distinct values in rows.
Sum	Sum of row values. Valid for numeric type columns.
SumDistinct	Sum of distinct values in rows. Valid for numeric type columns.
Avg	Average of row values. Valid for numeric type columns.
AvgDistinct	Average of distinct values in rows. Valid for numeric type columns.
Min	Minimum value in rows.
Max	Maximum value in row values.
StdDev	Standard deviation of row values.
DateDiff	Difference between two date values. Valid for date and datetime type columns.
DatePart	Crops out the specified part of date values and gives the kept part as number value. Valid for date and datetime type columns.
DateTrunc	Truncates date values except the specified date part and gives a date value. Valid for date and datetime type columns.