Exec
       sends a command to the backend server.  It's probably more desirable to
       use one of the next two functions.
ExecStatusType PgConnection::Exec(const char* query)
Returns the result status of the command. The following status results can be expected:
| PGRES_EMPTY_QUERY | 
| PGRES_COMMAND_OK, if the command was not a query | 
| PGRES_TUPLES_OK, if the query successfully returned tuples | 
| PGRES_COPY_OUT | 
| PGRES_COPY_IN | 
| PGRES_BAD_RESPONSE, if an unexpected response was received | 
| PGRES_NONFATAL_ERROR | 
| PGRES_FATAL_ERROR | 
       ExecCommandOk sends a non-query command
       (one that does not return rows) to the backend server.
int PgConnection::ExecCommandOk(const char *query)
Returns true (1) if the command succeeds.
       ExecTuplesOk
       Sends a query command (one that returns rows) to the backend server.
int PgConnection::ExecTuplesOk(const char *query)
Returns true (1) if the query succeeds.
       ErrorMessage
       returns the last error message text.
const char *PgConnection::ErrorMessage()
      Tuples
      returns the number of tuples (rows) in the query result. 
int PgDatabase::Tuples() const
      Fields
      returns the number of fields (rows) in each tuple of the query result. 
int PgDatabase::Fields()
      FieldName
      returns the field (column) name associated with the given field index. 
      Field indices start at 0. 
const char *PgDatabase::FieldName(int field_num) const
      FieldNum
      returns the field (column) index associated with 
      the given field name. 
int PgDatabase::FieldNum(const char* field_name) const
-1 is returned if the given name does not match any field.
      FieldType
      returns the field type associated with the given field index. The 
      integer returned is an internal coding of the type. Field indices
      start at 0. 
Oid PgDatabase::FieldType(int field_num) const
      FieldType
      returns the field type associated with the given field name. The 
      integer returned is an internal coding of the type. Field indices
      start at 0. 
Oid PgDatabase::FieldType(const char* field_name) const
      FieldSize
      returns the size in bytes of the field associated with the given 
      field index. Field indices start at 0. 
int PgDatabase::FieldSize(int field_num) const
Returns the space allocated for this field in a database tuple given the field number. In other words the size of the server's binary representation of the data type. -1 is returned if the field is variable size.
      FieldSize
      returns the size in bytes of the field associated with the given 
      field index. Field indices start at 0. 
int PgDatabase::FieldSize(const char *field_name) const
Returns the space allocated for this field in a database tuple given the field name. In other words the size of the server's binary representation of the data type. -1 is returned if the field is variable size.
      GetValue returns a single field (column)
      value of one tuple of a PGresult.
      Tuple and field indices start at 0.
const char *PgDatabase::GetValue(int tup_num, int field_num) const
      For most queries, the value returned by
      GetValue is a null-terminated string
      representation of the attribute value. But if
      BinaryTuples is true, the value returned by
      GetValue is the binary representation of
      the type in the internal format of the backend server (but not
      including the size word, if the field is variable-length). It is
      then the programmer's responsibility to cast and convert the
      data to the correct C type. The pointer returned by
      GetValue points to storage that is part of
      the PGresult structure. One should not
      modify it, and one must explicitly copy the value into other
      storage if it is to be used past the lifetime of the
      PGresult structure itself.
      BinaryTuples is not yet implemented.
     
      GetValue returns a single field (column)
      value of one tuple of a PGresult.
      Tuple and field indices start at 0.
const char *PgDatabase::GetValue(int tup_num, const char *field_name) const
      For most queries, the value returned by
      GetValue is a null-terminated string
      representation of the attribute value. But if
      BinaryTuples is true, the value returned by
      GetValue is the binary representation of
      the type in the internal format of the backend server (but not
      including the size word, if the field is variable-length). It is
      then the programmer's responsibility to cast and convert the
      data to the correct C type. The pointer returned by
      GetValue points to storage that is part of
      the PGresult structure. One should not
      modify it, and one must explicitly copy the value into other
      storage if it is to be used past the lifetime of the
      PGresult structure itself.
      BinaryTuples is not yet implemented.
     
      GetLength returns the length of a field
      (column) in bytes. Tuple and field indices start at 0.
int PgDatabase::GetLength(int tup_num, int field_num) const
      This is the actual data length for the particular data value,
      that is the size of the object pointed to by
      GetValue. Note that for
      character-represented values, this size has little to do with
      the binary size reported by PQfsize.
     
      GetLength returns the length of a field
      (column) in bytes. Tuple and field indices start at 0.
int PgDatabase::GetLength(int tup_num, const char* field_name) const
      This is the actual data length for the particular data value,
      that is the size of the object pointed to by
      GetValue. Note that for
      character-represented values, this size has little to do with
      the binary size reported by PQfsize.
     
      GetIsNull
      returns whether a field has the null value.
bool GetIsNull(int tup_num, int field_num) const
      Note that GetValue will return the empty
      string for null fields, not the NULL pointer.
     
      GetIsNull returns whether a field has the
      null value.
bool GetIsNull(int tup_num, const char *field_name) const
      Note that GetValue will return the empty
      string for null fields, not the NULL pointer.
     
      DisplayTuples prints out all the tuples
      and, optionally, the attribute names to the specified output
      stream.
void PgDatabase::DisplayTuples(FILE *out = 0, bool fillAlign = true, const char* fieldSep = "|", bool printHeader = true, bool quiet = false) const
This function is obsolescent.
      PrintTuples prints out all the tuples and,
      optionally, the attribute names to the specified output stream.
void PgDatabase::PrintTuples(FILE *out = 0, bool printAttName = true, bool terseOutput = false, bool fillAlign = false) const
This function is obsolescent.
      CmdTuples returns the number of rows
      affected after an INSERT,
      UPDATE, or DELETE.  If the
      command was anything else, it returns -1.
int PgDatabase::CmdTuples() const
      OidStatus
const char *PgDatabase::OidStatus() const