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6.4 Mysql

The mysql module provides interface to MySQL database management system. It may be used to build smap databases over SQL ones.

The SQL database to use may be configured either globally, when loading the module, or locally, when defining a smap database. If a database definition lacks SQL configuration statements, then it attempts to use a globally defined connection.

Each database is configured with a SQL query template, and a set of smap reply templates to use. When dispatched a sockmap query, the database expands the SQL query template using the actual values of ‘${map}’ (the map name) and ‘${key}’ (the key value) and sends the expanded query to the MySQL server. If the server responds with a non-empty set of tuples, the positive reply template is expanded and the result is used as a response. Otherwise, if the query produced an empty set, the smap database uses the negative reply template to create the response.