Each of the preprocessors works by taking the SQL statements that you have embedded in your COBOL program and converting them to the appropriate function calls to the database.
In your COBOL program, each embedded SQL statement must be preceded by the introductory keywords:
EXEC SQL
and followed by the keyword:
END-EXEC
For example:
EXEC SQL SELECT au_lname INTO :lastname FROM authors WHERE au_id = '124-59-3864' END-EXEC
The embedded SQL statement can be broken over as many lines as necessary following the normal COBOL rules for continuation, but between the EXEC SQL and END-EXEC keywords you can only code an embedded SQL statement, you cannot include any ordinary COBOL code.
Most vendors provide SQL Reference documentation with their database software which will include full information about embedded SQL statements but you should, for example, be able to perform the following typical operations using the statements shown:
A full syntax description is given for each of the embedded SQL statements, together with an example of its use, in the topic Embedded SQL Statements.