Wildcard Searching in Koha

by Joy Nelson on Dec 12, 2011

What is the difference between a keyword search using the ‘*’ (asterisk) versus a keyword search using the ‘%’ (percent)? Both work in the catalog, but return different sets. Why?

A wildcard is a character (*,?,%,.) that can be used to represent one or more characters in a word. Two of the wildcard characters that can be used in Koha searches are the asterisk (‘*’) and the percent sign (‘%’). However, these two characters act differently when used in searching.

The ‘*’ is going to force a more exact search of the first few characters you enter prior to the ‘*’. The asterisk will allow for an infinite number of characters in the search as long as the first few characters designated by your search remain the same. For example, searching for authors using the term, Smi*, will return a list that may include Smith, Smithers, Smithfield, Smiley, etc depending on the authors in your database.

The ‘%’ will treat the words you enter in the terms of “is like”. So a search of Smi% will search for words like Smi. This results in a much more varied results list. For example, a search on Smi% will return a list containing Smothers, Smith, Smelley, Smithfield and many others depending on what is your database.

The bottom line in searching with wildcards: ‘*’ is more exact while ‘%’ searches for like terms.