While the number and types of data elements or fields that compose a table entry vary from table to table, they all contain two similar definition fields, the code and a longer description. The code is usually an all upper-case abbreviation that represents or corresponds to the longer table entry description. For example, in the table of states, the standard 2-character abbreviation (TX) is the code, and the state name (Texas) is the description.
The code is a critical field and is:
■ The primary access key for the table entry through which the table entry is stored and retrieved
■ A validation check against input to the field it supports
In most fields, iMIS only lets you enter or select a code that exists in a table entry definition. In a field referencing the STATE_PROVINCE table, for example, iMIS would reject the code “TT” as not being a valid table entry.
In assigning codes, follow these guidelines:
■ Assign meaningful codes that best represent the description.
■ Make the codes long enough to be unique in the table but keep them as short as possible.
■ Do not use spaces, apostrophes ('), quotation marks (“), or special characters other than underscores.