每天睁眼看几遍，背下来就行了。
Field (abstract)
|
+--Field_bit
| +--Field_bit_as_char
|
+--Field_num (abstract)
| | +--Field_real (asbstract)
| | +--Field_decimal
| | +--Field_float
| | +--Field_double
| |
| +--Field_new_decimal
| +--Field_short
| +--Field_medium
| +--Field_long
| +--Field_longlong
| +--Field_tiny
| +--Field_year
|
+--Field_str (abstract)
| +--Field_longstr
| | +--Field_string
| | +--Field_varstring
| | +--Field_blob
| | +--Field_geom
| |
| +--Field_null
| +--Field_enum
| +--Field_set
|
+--Field_temporal (abstract)
+--Field_time_common (abstract)
| +--Field_time
| +--Field_timef
|
+--Field_temporal_with_date (abstract)
+--Field_newdate
+--Field_temporal_with_date_and_time (abstract)
+--Field_timestamp
+--Field_datetime
+--Field_temporal_with_date_and_timef (abstract)
+--Field_timestampf
+--Field_datetimef
