Embedded SQL for C (ESQL/C) programs incorporate Transact-SQL statements into C source code. But because you cannot directly submit ESQL/C programs to a C compiler, ESQL/C source programs must be processed by a precompiler that produces source code acceptable to a C compiler.
ESQL/C programming is a multistep development process that converts your original Embedded SQL source code into a Microsoft® SQL Server™ application that is an executable file compiled for the appropriate operating system.