Convert action field to enum

gistfile1.txt

mysql> create table test_enum (action varchar(255));
Query OK, 0 rows affected (0.05 sec)

mysql> insert into test_enum set action="create";
Query OK, 1 row affected (0.04 sec)

mysql> insert into test_enum set action="delete";
Query OK, 1 row affected (0.00 sec)

mysql> insert into test_enum set action="update";
Query OK, 1 row affected (0.00 sec)

mysql> alter table test_enum change action action enum("create", "delete", "update");
Query OK, 3 rows affected (0.11 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql> select * from test_enum;
+--------+
| action |
+--------+
| create |
| delete |
| update |
+--------+
3 rows in set (0.04 sec)

mysql> insert into test_enum set action="delete";
Query OK, 1 row affected (0.00 sec)

mysql> insert into test_enum set action=2;
Query OK, 1 row affected (0.00 sec)

mysql> select * from test_enum;
+--------+
| action |
+--------+
| create |
| delete |
| update |
| delete |
| delete |
+--------+
5 rows in set (0.00 sec)

mysql> select * from information_schema.tables where TABLE_NAME="test_audit_records_enum"\G
*************************** 1. row ***************************
  TABLE_CATALOG: def
   TABLE_SCHEMA: cloudpercept
     TABLE_NAME: test_audit_records_enum
     TABLE_TYPE: BASE TABLE
         ENGINE: InnoDB
        VERSION: 10
     ROW_FORMAT: Compact
     TABLE_ROWS: 1405719
 AVG_ROW_LENGTH: 148
    DATA_LENGTH: 208355328
MAX_DATA_LENGTH: 0
   INDEX_LENGTH: 102957056
      DATA_FREE: 4194304
 AUTO_INCREMENT: 65415819
    CREATE_TIME: 2013-10-31 16:17:31
    UPDATE_TIME: NULL
     CHECK_TIME: NULL
TABLE_COLLATION: latin1_swedish_ci
       CHECKSUM: NULL
 CREATE_OPTIONS: 
  TABLE_COMMENT: 
1 row in set (0.06 sec)

mysql> select * from information_schema.tables where TABLE_NAME="audit_records"\G
*************************** 1. row ***************************
  TABLE_CATALOG: def
   TABLE_SCHEMA: cloudpercept
     TABLE_NAME: audit_records
     TABLE_TYPE: BASE TABLE
         ENGINE: InnoDB
        VERSION: 10
     ROW_FORMAT: Compact
     TABLE_ROWS: 1460318
 AVG_ROW_LENGTH: 153
    DATA_LENGTH: 224100352
MAX_DATA_LENGTH: 0
   INDEX_LENGTH: 169967616
      DATA_FREE: 416284672
 AUTO_INCREMENT: 65415935
    CREATE_TIME: 2013-09-18 15:32:35
    UPDATE_TIME: NULL
     CHECK_TIME: NULL
TABLE_COLLATION: latin1_swedish_ci
       CHECKSUM: NULL
 CREATE_OPTIONS: 
  TABLE_COMMENT: 
1 row in set (0.00 sec)