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Full text search

For each country supported in the OpenPLZ API project there is a special API endpoint for full text search.

What is full-text search?

Full-text search in relational databases allows text in one or more columns to be searched based on the actual meaning of the words rather than a simple string match. The aim is to return the most relevant results possible when searching for specific terms - similar to a search engine.

For example, a search for "Monchengladbach" will also return results for "Mönchengladbach".

You can also enter the street, postal code and/or location in any order. The search entry 

Berlin Pariser Platz

returns the same result as

Pariser Platz, Berlin

How exactly does the full-text search work?

We use the PostgreSQL full-text search in the background, more precisely the function websearch_to_tsquery. This function allows the input of unformatted text and converts it into the appropriate target format for PostgreSQL:

  • Text that is not in inverted commas is converted to terms separated by & operators, as when processed by plainto_tsquery.

  • Text in ‘inverted commas’ is converted into terms separated by <-> operators, as if they were being processed by phraseto_tsquery.

  • An OR is converted to the | operator.

  • A hyphen - is converted into the operator !.

  • Other special characters, e.g. full stop, comma, exclamation mark etc. are ignored.

Where can I find the full text search?

The following API endpoints allow a full text search via street name, postal code and location name:

  • at/FullTextSearch
  • ch/FullTextSearch
  • de/FullTextSearch
  • li/FullTextSearch

It's best just to try it out.