The characters recognized by Adaptive Server are limited in part by the language of the installation and the default character set. Therefore, the characters allowed in SQL statements and in the data contained in the server vary from installation to installation and are determined in part by definitions in the default character set.
SQL statements must follow precise syntactical and structural rules, and can contain operators, constants, SQL keywords, special characters, and identifiers. Identifiers are objects within the server, such as database names or table names. Naming conventions vary for some parts of the SQL statement. Operator, constants, SQL keywords, and Transact-SQL extensions must adhere to stricter naming restrictions than identifiers, which themselves cannot contain operators and special characters. However, the data contained within the server can be named following more permissive rules. Figure 1-2 illustrates these relationships.
Figure 1-2: Naming conventions governing SQL statements
The sections that follow describe the sets of characters that can be used for each part of a statement. The section on identifiers also describes naming conventions for database objects.
