On Tue, May 19, 2009 at 02:17:20PM +0200, Sebastien FLAESCH wrote: > As you can do with ODBC's SQLBindParameter(), where you specify the C type, > SQL type, precision/scale or length ... > I believe this is important when it comes to data type conversion (for ex, > when you want to insert a numeric/date/time into a char or the other way). > => sort of cast, actually... Tom sent a message, but it seems to have got lost somewhere. The suggestion was to leave the paramTypes empty and just write the prepared statement as: INSERT INTO tbl (k,i1,i2) VALUES ($1::INT,$2::INTERVAL YEAR,$3::INTERVAL); or similar. That way PG will be able to infer that $1 will be a literal of integer type, $2 will be of INTERVAL YEAR and so on. In fact for queries such as this I don't think you even need to put those casts in there as PG will be able to figure out what you mean automatically (i.e. it does a limited form of type inference). > I known libpq functions like PQexecParams() or PQexecPrepared() have a > paramFormats[] parameter to specify if the buffer will hold a string > or the binary representation of the value... but that would not help > much (I don't want to deal with internal structures!). Yes, stay away from binary types if at all possible! > Also: I still have the overflow issue with types like INTERVAL SECOND. > => discussed in another thread "INTERVAL SECOND limited to 59 seconds?" If I read it correctly; it's not overflow but truncation. In PG (I've got no idea what the database you're comparing to does/what the spec says it's supposed to do) when you you want a value of type "INTERVAL SECOND" then PG is interpreting this as meaning I want a value of type INTERVAL where all the fields apart from the seconds are zero. Whether this is useful seems debatable, Richard's suggestion of creating a set of custom types that do the right thing for you seems like the path of least resistance. -- Sam http://samason.me.uk/ -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
