#657 MySQL Json fields always return empty strings

[Artie]

Currently, Zeoslib does not support json field in MySQL.
If I cast the field as string, I will always get an empty string. A few modification will make it work.

procedure TZAbstractMySQLResultSet.InitColumnBinds(Bind: PMYSQL_aligned_BIND;
  MYSQL_FIELD: PMYSQL_FIELD; FieldOffsets: PMYSQL_FIELDOFFSETS; Iters: Integer);
begin
  Bind^.is_unsigned_address^ := Ord(PUInt(PAnsiChar(MYSQL_FIELD)+FieldOffsets.flags)^ and UNSIGNED_FLAG <> 0);
  bind^.buffer_type_address^ := PMysqlFieldType(PAnsiChar(MYSQL_FIELD)+FieldOffsets._type)^; //safe initialtype
  if FieldOffsets.charsetnr > 0
  then bind^.binary := (PUInt(PAnsiChar(MYSQL_FIELD)+FieldOffsets.charsetnr)^ = 63) and (PUInt(PAnsiChar(MYSQL_FIELD)+FieldOffsets.flags)^ and BINARY_FLAG <> 0)
  else bind^.binary := (PUInt(PAnsiChar(MYSQL_FIELD)+FieldOffsets.flags)^ and BINARY_FLAG <> 0);
  // add the following lines
  if bind^.buffer_type_address^ = MYSQL_TYPE_JSON then
    bind^.binary := False;
  //...