- Method query
array(mapping(string:mixed)) query(string sqlquery)
This is all you need to query the database. It takes as argument an SQL query string (i.e.: "SELECT foo,bar FROM baz WHERE name like '%kinkie%'" or "INSERT INTO baz VALUES ('kinkie','made','this')") and returns a data structure containing the returned values. The structure is an array (one entry for each returned row) of mappings which have the column name as index and the column contents as data. So to access a result from the first example you would have to do "results->foo".
A query which returns no data results in an empty array (and NOT in a 0). Also notice that when there is a column name clash (that is: when you join two or more tables which have columns with the same name), the clashing columns are renamed to <tablename>+"."+<column name>. To access those you'll have to use the indexing operator ' (i.e.: results["foo.bar"]).
Errors (both from the interface and the SQL server) are reported via exceptions, and you definitely want to catch them. Error messages are not particularly verbose, since they account only for errors inside the driver. To get server-related error messages, you have to use the error function.
Note that if the query is NOT a of SELECT type, but UPDATE or MODIFY, the returned value is an empty array. This is not an error. Errors are reported only via exceptions.
- See also