Progress
Language Reference
MATCHES Operator
Compares a character expression to a pattern and evaluates to a TRUE value if the expression satisfies the pattern criteria.
SYNTAX
expression
A character expression that you want to check to see if it conforms with the pattern.
pattern
A character expression that you want to match with the string. This can include a constant, field name, variable name, or expression whose value is a character.
The pattern can contain wildcard characters: a period (.) in a particular position indicates that any single character is acceptable in that position; an asterisk (*) indicates that any group of characters is acceptable, including a null group of characters.
EXAMPLEThis procedure displays customer information for all customers whose address ends in St. The procedure does not use an index for the customer search in
r-match.p
.
NOTES
- MATCHES does not use index information when performing a comparison; it always scans the entire data table.
- MATCHES does not ignore trailing blanks as does the equal (EQ) comparison operator. Thus, “abc” does not match “abc “ although they are considered equal.
- Most character comparisons are case insensitive in Progress. By default, all characters are converted to uppercase prior to comparisons. However, you can define fields and variables as case sensitive (although it is not advised, unless strict ANSI SQL adherence is required). If the expression preceding the MATCHES keyword is a field or variable defined as case sensitive, the comparison is case sensitive. In a case-sensitive comparison “SMITH” does not equal “Smith”.
- If you want to specify a period ( . ) or an asterisk (a constant, field name, variable name, or expression whose value is character)( * ) as a literal character rather than a wildcard character in the pattern, enter a tilde (~) before the character. For example, the result of “*a.b” MATCHES “~*a.~.b” is TRUE. If you specify the match pattern as a literal quoted string in a procedure file, enter each tilde as a double tilde ( ~ ~ ) so that they are interpreted as tildes for the match pattern.
- The MATCHES function is double-byte enabled. Both the specified expression and pattern arguments can contain double-byte characters.
SEE ALSO
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