Embedded SQL statements are SQL statements written within application programming languages such as C and preprocessed by an SQL preprocessor before the application program is compiled. There are two types of embedded SQL: static and dynamic.
The source form of a static SQL statement is embedded within an application program written in a host language such as COBOL. The statement is prepared before the program is executed and the operational form of the statement persists beyond the execution of the program.
A source program containing static SQL statements must be processed by an SQL precompiler before it is compiled. The precompiler turns the SQL statements into host language comments, and generates host language statements to invoke the database manager. The syntax of the SQL statements is checked during the binding process.
The preparation of an SQL application program includes precompilation, the binding of its static SQL statements to the target database, and compilation of the modified source program. The steps are specified in the Embedded SQL Programming Guide.
Programs containing embedded dynamic SQL statements must be precompiled like those containing static SQL, but unlike static SQL, the dynamic SQL statements are constructed and prepared at run time. The SQL statement text is prepared and executed using either the PREPARE and EXECUTE statements, or the EXECUTE IMMEDIATE statement. The statement can also be executed with the cursor operations if it is a SELECT statement.