Because a UAP source file in which SQL statements are embedded cannot be executed directly, an SQL preprocessor must be executed. Executing the SQL preprocessor converts the embedded SQL statements into a high-level language description. This process of converting a UAP source to a post source that can be converted by a language compiler by executing the SQL preprocessor is called preprocessing.

The SQL preprocessor creates a high-level language function corresponding to the SQL statements and embeds it in the source. During this process, the SQL preprocessor checks the validity of the data types and values of the variables, as well as the syntax of various names. If the checking results indicate that an error was detected in the input source program, a message to that effect is output to the standard error output.

The SQL preprocessor does not check the following items:

• If there are any table names for which a query needs to be addressed to the server
• If there are any column names for which a query needs to be addressed to the server
• If there are other identifiers, data types, or functions for which a query needs to be addressed to the server
• Table access privileges

1. The setting of environment variables and the command specification methods differ depending on the language used in the source program and the environment. The SQL preprocessor must therefore match the language and the environment being used.
2. In the Windows environment, the SQL preprocessor cannot perform a rigorous SQL syntax check unless /Xp is specified. Therefore, the preprocessor may not be able to detect all syntax errors in the SQL statements. Also, with Linux for AP8000 and AIX 5L clients, the SQL preprocessor cannot perform a rigorous SQL syntax check if a character code type other than SJIS is used.
3. In the Windows environment, only sjis and lang-c character codes can be used because EUC codes cannot be recognized. If a value other than sjis or lang-c is specified as the character code type in the HiRDB server, an error occurs when a HiRDB client executes a UAP.