Overview#Greater-Or-Equal SearchFilter is a type of LDAP Filter Choice that is used to determine whether an entry contains at least one value for a specified attribute that is greater than or equal to a provided value.
If an entry has one or more values for an attribute that are determined to be greater than or equal to the target value, then the LDAP SearchFilter will match that entry, even if it has other values that are determined to be less than the target value.
The string representation of a greater-or-equal filter is constructed as follows:
- An open parenthesis
- The attribute description (potentially including attribute options)
- A greater-than symbol
- An equal sign
- The value to compare (aka the Assertion Value)
- A close parenthesis
The determination of whether one value is greater than or equal to another is the function of the ORDERING matching Rule for the attribute type, and the logic used may vary from one attribute type to another.
For some kinds of attributes, it may not even make sense to try to make an ordering comparison (e.g., for an attribute type whose values are intended to be the names of colors, it doesn't make any sense to ask if the color red is greater than or equal to the color blue), and therefore those attributes may not have an ordering matching rule. Matching rules will be discussed in greater detail in the chapter on LDAP schema.
For example, a greater or equal filter of "(createTimestamp>=20070101000000Z)" will match any entry that has a createTimestamp value that is greater than or equal to "20070101000000Z".