PRB: ADSI LDAP Filters Ignore Queries That Contain > or < Operator (260045)


The information in this article applies to:

  • Microsoft Active Directory Service Interfaces 2.5
  • Microsoft Active Directory Service Interfaces 2.0
  • Microsoft Active Directory Services Interface, System Component, when used with:
    • the operating system: Microsoft Windows 2000
This article was previously published under Q260045

SYMPTOMS

Active Directory Services Interfaces (ADSI) queries that use the > (greater than) or < (less than) operators may result in empty result sets, even though values in the directory satisfy the filter.

CAUSE

ADSI follows the Request for Comments (RFC) 2254 specification for forming Lightweight Data Access Protocol (LDAP) version 3 search filters. RFC 2254 states that "greater than" should be expressed as >= and "less than" should be expressed as <=. For this reason, ADSI treats queries that use the > or < operator as malformed, and does not pass these queries to the directory server.

RESOLUTION

To work around this problem, rework the query to use >= or <=, and then exclude all occurrences of equality. For example, you could rework the following filter 
(MyAttribute>MyValue)
in this way: 
(&(MyAttribute>=MyValue)(!(MyAttribute=MyValue)))

STATUS

This behavior is by design.

MORE INFORMATION

You can specify queries with ADSI through the OLE DB provider and IDirectorySearch interface. You can express these queries by using an LDAP syntax or an SQL syntax. When you use the LDAP syntax, you must adhere to the RFC syntax described above. When you use the SQL syntax, the ADSI parser performs the conversion (to the RFC syntax) automatically.

REFERENCES

For additional information on LDAP RFCs (including RFC 2254), click the article number below to view the article in the Microsoft Knowledge Base:

221606 Common LDAP RFCs

For additional information on using LDAP queries from ADSI, see the following article:

187529 HOWTO: Using ADO to Access Objects Through ADSI LDAP Provider

For general information on ADSI, please see the following Web site:

http://www.microsoft.com/adsi

Modification Type:MajorLast Reviewed:3/11/2004
Keywords:kbMsg kbprb KB260045
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