The INCLUDE statement is very much like the C preprocessor #include directive. The SQL preprocessor reads an embedded SQL
source file and replaces all the embedded SQL statements with C-language source code. If a file contains information that
the SQL preprocessor requires, include it with the embedded SQL INCLUDE statement.
Two file names are specially recognized: SQLCA and SQLDA. The following statement must appear before any embedded SQL statements
in all embedded SQL source files.
EXEC SQL INCLUDE SQLCA;
This statement must appear at a position in the C program where static variable declarations are allowed. Many embedded SQL
statements require variables (invisible to the application developer), which are declared by the SQL preprocessor at the position
of the SQLCA include statement. The SQLDA file must be included if any SQLDAs are used.