Database connection

One of the main features of a GIS is the connection to a database. Some tables from a database can be joined with the spatial data. That means that the spatial data contain a numerical key code from a sql table. For example the code of soil data. This code points to an external database table. Some columns of this table contain information like agricultural data, some data about the ground water etc.. To use this information you must know the table name, the name of the column with the key and the name of the column to join. This three data are inputs in the parameter P1, P2, P3 and a new grid will be generated. The name of this grid is the name of the third parameter (column to join). To use such a database connection to MySQL you need an init file called .my.cnf with:

This file must be in the same directory like SAMT. The database must not be on the same computer like SAMT. It is good if it is in the network. If no database is available then the same joining procedure can be made with a simple text file (separated with blank). This file must be in the directory test. This is useful for simple projects without a database.
To browse over the database you can use mysqlcc for example (or a other gui of mysql).