OpenEdge Data Management: DataServer for Microsoft SQL Server

Chapter 2: Initial Programming Considerations
Naming conventions
When planning for maximum transparency across OpenEdge databases and MS SQL
Server data sources, be sure to consider the restrictions that each places on naming
data source objects when you perform a OpenEdge DB to MS SQL Server conversion.
Table 6 describes these restrictions, and the notes that follow discuss how the
DataServer resolves differences between OpenEdge and MS SQL Server database
naming conventions.
Table 6: Database naming restrictions
Alphanumeric
characters
Category OpenEdge MS SQL Server
A–Z or a–z
0–9
Special characters Allows $, &, #, %, –,
and _ 1
All alphanumeric characters
from the character set that you
defined for your MS SQL
Server
Allows @, $, #, _, ¥, and £ 2
Initial character Alphabetic only Alphabetic only
Maximum length of
object name
Keywords Not allowed 4
Unique table names Required 5
32 characters 24 characters 3
Not allowed 4
Required 6
1. Although OpenEdge allows you to use the ampersand (&) in database-object names, the OpenEdge
development tools use this character internally to denote preprocessor directives.
2. When the DataServer encounters characters not supported by OpenEdge in a sequence, table, index, or
field name, it converts them to underscores ( _ ) in the data source. For example, the data source table
name emp@status becomes emp_status in the schema holder. If the unsupported character is at the
beginning of an object name, the DataServer substitutes a lowercase z. Also, the DataServer strips @
symbols from stored procedure parameter names.
3. Object names are limited to 32 characters. When you use the OpenEdge DB to MS SQL Server utility to
perform a database conversion, however, the utility truncates object names to 24 characters in order to
accommodate the suffix characters that it appends when it finds nonunique names, reused OpenEdge
keywords, array fields, sequences, triggers, and so forth. If you intend to use the OpenEdge DB to MS
SQL Server utility, be sure to limit object names to 24 characters to accommodate this name resolution
during conversion.
4. OpenEdge and MS SQL Server databases contain restrictions against using keywords as database object
names. If a data source object name consists of an OpenEdge keyword, the DataServer appends an
underscore character ( _ ) to the name. For example, an object named “each” becomes “each_”
5. MS SQL Server qualifies nonunique table names to make them unique (see your data source
documentation for details); however, OpenEdge still regards these qualified names as nonunique. The
DataServer resolves nonunique table names for you as follows: when OpenEdge encounters matching
table names while creating or updating a schema holder, it names the second and subsequent tables
table-1, table-2, etc. For example, if OpenEdge encounters a table named lee.employee (the employee
table owned by the user lee) that is the second instance of the name in the data source, it names the
corresponding table in the schema holder employee-1. Keep in mind that when resolving naming
conventions, the DataServer can append up to three characters to an object name: two in the case of a
nonunique name and one in the case of an OpenEdge keyword. Therefore, you should limit your object
names to 29 characters so that you do not exceed the OpenEdge 32-character limit for object names in
the schema holder.
6. MS SQL Server allows you to qualify an object name by adding the database name, the owner’s name,
or the table name (for columns).
58 OpenEdge Data Management: DataServer for Microsoft SQL Server