The following rules apply to table names:
- They are restricted to 20 characters.
- They may only contain alphanumeric values and the underline sign (no spaces).
- They must begin with a letter.
- You may not use a reserved word (a list of reserved words appears in the Reserved Words form — System Management → Dictionaries).
- The name of any new table (one you have added yourself) must begin with a four-letter prefix (e.g., XXXX_CUSTOMERS). All tables (and any other Priority entities) that you have created for the same customer should share the same prefix.
The table type determines whether the table is an application table or a system table. An application table is a table in which data is maintained separately for each Priority company, whereas a system table is used to store data that is common to all companies in the current Priority installation.
For historical reasons,Priority lists 4 possible values in the TYPE column:
- 0/1 – for application tables
- 2/3 – for system tables
However, new tables should always be assigned type 0.
Note: You cannot create new system tables or add new columns to system tables.
If users at a customer site work in a language other than English, you will need to install revisions in more than one language. Before you even begin programming for such a customer, enter the System Constants form (System Management → System Maintenance → Constant Forms) and change the value of the UPGTITLES constant to 0. Consequently, no titles (in any language) will be stored in the upgrade file; rather, they will be inserted into a second file (based on the upgrade file) via another program.
Note: For more on preparing upgrades for other languages, see Customizations: Installing the Language Dictionaries.
Rules for Modifying Tables and Table Columns
- When modifying tables, do not change standard table columns or any of the table’s unique (or Auto Unique) keys.
- If you add a column to the table, the column name must begin with a four-letter prefix. Use the same prefix for all table columns (as well as any other Priority entities) that you have added for a given customer.
- When creating a new table, the table name should begin with the appropriate four-letter prefix (there is no need to add this prefix to the new table’s columns).
When Installing a Revision with Modifications of a Standard Table
- Ensure that all users have exited the system.
Note: For general guidelines for development, see Working with Version Revisions.