Statement

sql holder and executer. JDBC has three statement classes: Statement, PreparedStatement, and CallableStatement. RDBC has only one statement class.

initialize(con, sql=nil)

You dont have to call it yourself. if sql==nil then self is non-prepared. else self is prepared.

execute(sql=nil)

execute sql. if sql==nil then prepared sql is executed. else the sql is executed.
returns true if a ResultSet object is made. return false if updatecount>=0.

executeQuery(sql=nil)

execute. throws an exception if ResultSet object is not made. returns the ResultSet object.

executeUpdate(sql=nil)

execute. throws an exception if updatecount < 0. returns updatecount.

close

setParam(index, data)

if prepared, you can "set a data to a parameter". index is a name(String) of the parameter.

getParam(index)

if prepared, you can "get a data from a parameter". index is a name(String) of the parameter.

resultset

returns recent ResultSet object. executeUpdate discards(nil) the object.

updatecount

returns recent updatecount. executeQuery discards(-1) the value.