`information_schema.statistics.column_name`

mysql

type: VARCHAR NULL

type: VARCHAR NOT NULL

5.7

type: NULL

Note:

Column name.

5.1-10.8

type: VARCHAR NOT NULL

Note:

Column name.

type: VARCHAR(21) NULL

Note:

The column name. See the description of the Expression column.

4-6.1

type: unknown

Note:

Name of the column being indexed.

1-21.2