+namespace SQL
+{
+ class Error;
+ class Field;
+ class Provider;
+ class Query;
+ class Result;
+
+ /** A list of parameter replacement values. */
+ typedef std::vector<std::string> ParamList;
+
+ /** A map of parameter replacement values. */
+ typedef std::map<std::string, std::string> ParamMap;
+
+ /** A list of SQL fields from a specific row. */
+ typedef std::vector<Field> Row;
+
+ /** An enumeration of possible error codes. */
+ enum ErrorCode
+ {
+ /** No error has occurred. */
+ SUCCESS,
+
+ /** The database identifier is invalid. */
+ BAD_DBID,
+
+ /** The database connection has failed. */
+ BAD_CONN,
+
+ /** Executing the query failed. */
+ QSEND_FAIL,