Datasource Meta Information

All datasources must provide functions to access their meta information. If the datasource is a database, such metainformation are the names of the tables, the columns, user rights, and so on. The results from a meta information query is represented as a Gda_Recordset. The problem is that most of the time the client is only interested in some part of the information. The client wants to query the data source about the indices for a table, not all indices for all tables. Therefore it is possible to pass conmstraints to the meta information query. But this is further complicated by he fact that each query might want to have different constraints. The following list will show which query types are implemented and which constraints are volid for each query. The constraints are passsed as name-value pairs. The name is an enum and the value is a string. The query function is a variadic function and the argument list must be closed with a enum value of 0.

For example a query about all tables of a datasource will look like: gda_connection_open_schem(cnc, GDCN_SCHEMA_TABLES, TABLE_TYPE, "USER", 0);

The exact sematics and the valid strings for each constraint is data surce depenedent and should be documented there.