There are several types for each field (column) type, such as type()/real_type()/binlog_type() ...
By default, real_type() and binlog_type() are the same as type():
// From mysql-8.0/sql/field.h Field
// ...
virtual enum_field_types real_type() const { return type(); }
virtual enum_field_types binlog_type() const {
/*
Binlog stores field->type() as type code by default.
This puts MYSQL_TYPE_STRING in case of CHAR, VARCHAR, SET and ENUM,
with extra data type details put into metadata.
We cannot store field->type() in case of temporal types with
fractional seconds: TIME(n), DATETIME(n) and TIMESTAMP(n),
because binlog records with MYSQL_TYPE_TIME, MYSQL_TYPE_DATETIME
type codes do not have metadata.
So for temporal data types with fractional seconds we'll store
real_type() type codes instead, i.e.
MYSQL_TYPE_TIME2, MYSQL_TYPE_DATETIME2, MYSQL_TYPE_TIMESTAMP2,
and put precision into metatada.
Note: perhaps binlog should eventually be modified to store
real_type() instead of type() for all column types.
*/
return type();
}
// ...
Here is a list collected from mysql-8.0/sql/field.h:
+------------------------------------------------------------+-------------------------------+-----------------------+------------------------+
| Field | type() | real_type() | binlog_type() |
+------------------------------------------------------------+-------------------------------+-----------------------+------------------------+
| | | | |
| Field (abstract) | | | |
| | | | | |
| +--Field_bit | MYSQL_TYPE_BIT | | |
| | +--Field_bit_as_char | | | |
| | | | | |
| +--Field_num (abstract) | | | |
| | | +--Field_real (abstract) | | | |
| | | +--Field_decimal | MYSQL_TYPE_DECIMAL | | |
| | | +--Field_float | MYSQL_TYPE_FLOAT | | |
| | | +--Field_double | MYSQL_TYPE_DOUBLE | | |
| | | | | | |
| | +--Field_new_decimal | MYSQL_TYPE_NEWDECIMAL | | |
| | +--Field_short | MYSQL_TYPE_SHORT | | |
| | +--Field_medium | MYSQL_TYPE_INT24 | | |
| | +--Field_long | MYSQL_TYPE_LONG | | |
| | +--Field_longlong | MYSQL_TYPE_LONGLONG | | |
| | +--Field_tiny | MYSQL_TYPE_TINY | | |
| | +--Field_year | MYSQL_TYPE_YEAR | | |
| | | | | |
| +--Field_str (abstract) | | | |
| | +--Field_longstr | | | |
| | | +--Field_string | MYSQL_TYPE_STRING | MYSQL_TYPE_STRING | |
| | | +--Field_varstring | MYSQL_TYPE_VARCHAR | MYSQL_TYPE_VARCHAR | |
| | | +--Field_blob | MYSQL_TYPE_BLOB | | |
| | | +--Field_geom | MYSQL_TYPE_GEOMETRY | | |
| | | +--Field_vector | MYSQL_TYPE_VECTOR | | |
| | | +--Field_json | MYSQL_TYPE_JSON | | |
| | | +--Field_typed_array | real_type_to_type(m_elt_type) | m_elt_type | MYSQL_TYPE_TYPED_ARRAY |
| | | | | | |
| | +--Field_null | MYSQL_TYPE_NULL | | |
| | +--Field_enum | MYSQL_TYPE_STRING | MYSQL_TYPE_ENUM | |
| | +--Field_set | | MYSQL_TYPE_SET | |
| | | | | |
| +--Field_temporal (abstract) | | | |
| +--Field_time_common (abstract) | | | |
| | +--Field_time | MYSQL_TYPE_TIME | | |
| | +--Field_timef | MYSQL_TYPE_TIME | MYSQL_TYPE_TIME2 | MYSQL_TYPE_TIME2 |
| | | | | |
| +--Field_temporal_with_date (abstract) | | | |
| +--Field_newdate | MYSQL_TYPE_DATE | MYSQL_TYPE_NEWDATE | |
| +--Field_temporal_with_date_and_time (abstract) | | | |
| +--Field_timestamp | MYSQL_TYPE_TIMESTAMP | | |
| +--Field_datetime | MYSQL_TYPE_DATETIME | | |
| +--Field_temporal_with_date_and_timef (abstract) | | | |
| +--Field_timestampf | MYSQL_TYPE_TIMESTAMP | MYSQL_TYPE_TIMESTAMP2 | MYSQL_TYPE_TIMESTAMP2 |
| +--Field_datetimef | MYSQL_TYPE_DATETIME | MYSQL_TYPE_DATETIME2 | MYSQL_TYPE_DATETIME2 |
+------------------------------------------------------------+-------------------------------+-----------------------+------------------------+