Difference Between EXEC SQL DECLARE and EXEC SQL INCLUDE in Pro*C

In Pro*C, the focus keyword for this discussion is "EXEC SQL DECLARE" and "EXEC SQL INCLUDE".

EXEC SQL DECLARE

The "EXEC SQL DECLARE" statement is used to declare host variables and cursor variables explicitly before they are used in embedded SQL statements. This allows the Pro*C compiler to recognize the data types of the variables during the precompilation stage.

EXEC SQL INCLUDE

On the other hand, the "EXEC SQL INCLUDE" statement is used to include external SQL declarations from an external SQL source file into the Pro*C code. This allows for modularization and reuse of SQL statements across multiple Pro*C programs.

Overall, the key difference between "EXEC SQL DECLARE" and "EXEC SQL INCLUDE" lies in their functionality regarding variable and SQL statement declarations in Pro*C programs.