MATCHES Predicate
Note
Indexing Service is no longer supported as of Windows XP and is unavailable for use as of Windows 8. Instead, use Windows Search for client side search and Microsoft Search Server Express for server side search.
The MATCHES predicate performs queries using regular-expression pattern matching, which is more powerful than the wildcard pattern matching available with the LIKE predicate. This predicate is an optional part of the optional WHERE clause of the SELECT statement.
SELECT Select_List | *
FROM_Clause
[WHERE MATCHES(Column_Reference, ' {Grouped_Search_Pattern | Counted_Search_Pattern} ') ]
[ORDER_BY_Clause]
Parameters
-
Select_List
-
Specifies the list of column aliases (properties) making up the table (rowset) that is returned as a result of the query.
-
* (asterisk)
-
Specifies all columns. This option is valid only when the FROM_Clause parameter references a predefined view or a temporary view.
-
FROM_Clause
-
Specifies the files on which to perform the search. For details about this parameter, see FROM Clause.
-
Column_Reference
-
Specifies the column name (alias). Its data type must be compatible with the format of the Search_Pattern parameter specified.
-
Grouped_Search_Pattern
-
Specifies matches against multiple patterns.
-
Counted_Search_Pattern
-
Specifies searches for repetitions of the same pattern. You can request:
- Exactly m matches: "m"
- At least m matches: "m,"
- Between m and n occurrences of the search pattern: "m,n"
-
ORDER_BY_Clause
-
Specifies the ordering of the resulting rowset. This clause is optional. For details about this parameter, see ORDER BY Clause.
Remarks
Index Server 1.x and 2.0 required a > 0 comparison operation at the end of the MATCHES predicate, for example, MATCHES( … ) >0. Beginning with Indexing Service 3.0, the comparison operation is neither required nor recommended, but it is supported for backward compatibility.
A grouped or counted search pattern is formed like a literal of type Basic String but consists of a combination of characters and regular expressions (match symbols). Indexing Service is not case sensitive to characters in a search pattern other than the match symbols. The following table lists and describes the regular expressions that you can use with the MATCH predicate:
| Name | Symbol | Description |
|---|---|---|
| Asterisk | * | Matches 0 or more occurrences of the search pattern. |
| Question mark | ? | Matches 0 or 1 occurrence of the preceding pattern. |
| Plus sign | + | Matches 1 or more occurrences of the preceding pattern. |
| Parentheses | ( ) | Used to delimit search patterns > 1 character. |
| Curly braces | { } | Used to delimit a counted match. |
| Square Brackets | [ ] | Used to specify a range of characters in a pattern. |
| Vertical bar | | | Used as an escape character that must precede any of the above symbols. Commas separating OR clauses in the matching terms must also be preceded by the escape character. |
Examples
The following example uses a grouped match. The pattern matches text with the strings "McAlister", and "McAllister" (strings such as "McAlllister", if they existed, would also be matched). Note how the vertical-bar escape character precedes the embedded regular-expression symbols.
... WHERE MATCHES (Contents, 'McAl|+ister' )
The following example matches any string in which exactly three instances of the pattern "Bora" occur.
... WHERE MATCHES (Contents, '|(Bora|)|{3|}' )
The following example matches any string in which at least two instances of the pattern "Bora" occurs.
... WHERE MATCHES (Contents, '|(Bora|)|{2,|}' )
The following example matches any string in which between two and three instances of the pattern "Bora" occurs.
... WHERE MATCHES (Contents, '|(Bora|)|{2,3|}' )
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