28.4.11 The INFORMATION_SCHEMA INNODB_FIELDS Table

The INNODB_FIELDS table provides metadata about the key columns (fields) of InnoDB indexes.

For related usage information and examples, see Section 17.15.3, “InnoDB INFORMATION_SCHEMA Schema Object Tables”.

The INNODB_FIELDS table has these columns:

• INDEX_ID

  An identifier for the index associated with this key field; the same value as INNODB_INDEXES.INDEX_ID.

• NAME

  The name of the original column from the table; the same value as INNODB_COLUMNS.NAME.

• POS

  The ordinal position of the key field within the index, starting from 0 and incrementing sequentially. When a column is dropped, the remaining columns are reordered so that the sequence has no gaps.

Example

mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_FIELDS WHERE INDEX_ID = 117\G
*************************** 1. row ***************************
INDEX_ID: 117
    NAME: col1
     POS: 0

Notes

• You must have the PROCESS privilege to query this table.

• Use the INFORMATION_SCHEMA COLUMNS table or the SHOW COLUMNS statement to view additional information about the columns of this table, including data types and default values.