# Columns

The length of a column name must be less than or equal to 30 characters. The following conventions apply when you define special types of columns in the database.

Use the suffix FLG to define a lookup table field. Flag columns must be CHAR(4). Choose lookup field names carefully as these column names are defined in the lookup table (CI_LOOKUP_FLD) and must be prefixed by the product owner flag value.

Use the suffix CD to define user-defined codes. User-defined codes are primarily found as the key column of the admin tables.

Use the suffix ID to define system assigned key columns.

Use the suffix SW to define Boolean columns. The valid values of the switches are 'Y' or 'N'. The switch columns must be CHAR(1)

Use the suffix DT to define Date columns.

Use the suffix DTTM to define Date Time columns.

Use the suffix TM to define Time columns.

Some examples are:

- ADJ_STATUS_FLG
- CAN_RSN_CD

Parent topic: Naming Standards