>>--EXEC SQL---OPEN---cursor_name------------------------> >----.--------------------------------.----END-EXEC----->< +-USING DESCRIPTOR :sqlda_struct-+ | +- , -+ | | V | | +-USING :hvar--------------------+
|cursor_name||A previously declared cursor.|
|:sqlda_struct||An SQLDA data structure previously constructed by the application. The SQLDA data structure contains the address, data type, and length of each input parameter. This option is used only with a cursor that references a prepared SQL statement in the DECLARE statement. The colon is optional to provide compatibility with other embedded SQL implementations.|
|:hvar||One or more input host variables corresponding to parameter markers in the SELECT statement. This option is used only with a cursor that references a prepared SQL statement in the DECLARE statement.|
If the cursor is declared with a static SELECT statement (that is, one that was not prepared), the SELECT statement can contain host variables but not parameter markers . The current values of the host variables are substituted when the OPEN statement runs. For a statically declared cursor, the OPEN statement cannot contain the USING :hvar or USING DESCRIPTOR :sqlda_struct option.
If the cursor is declared with a dynamic SELECT statement (that is, one that was prepared), the SELECT statement can contain parameter markers but not host variables. Parameter markers can appear wherever column values are allowed in the SELECT statement. If the SELECT statement has parameter markers, the OPEN statement must include either the USING :hvar option with the same number of host variables or the USING DESCRIPTOR :sqlda_struct option identifying an SQLDA data structure already populated by the application.
With the USING DESCRIPTOR :sqlda_struct option, values of the program variables are substituted for parameter markers in the SELECT statement. These program variables are addressed by corresponding SQLDATA entries in the SQLDA data structure.
The number of parameter markers in the SELECT statement must match the number of sqldata entries (USING DESCRIPTOR :sqlda_struct) or host variables (USING :hvar) in the OPEN statement.
*Declare the cursor... EXEC SQL DECLARE C1 CURSOR FOR SELECT staff_id, last_name FROM staff END-EXEC IF SQLCODE NOT = ZERO DISPLAY 'Error: Could not declare cursor.' DISPLAY SQLERRMC DISPLAY SQLERRML EXEC SQL DISCONNECT ALL END-EXEC STOP RUN END-IF EXEC SQL OPEN C1 END-EXEC IF SQLCODE NOT = ZERO DISPLAY 'Error: Could not open cursor.' DISPLAY SQLERRMC DISPLAY SQLERRML EXEC SQL DISCONNECT CURRENT END-EXEC STOP RUN END-IF PERFORM UNTIL sqlcode NOT = ZERO *SQLCODE will be zero as long as it has successfully fetched data EXEC SQL FETCH C1 INTO :staff-staff-id, :staff-last-name END-EXEC IF SQLCODE = ZERO DISPLAY "Staff ID: " staff-staff-id DISPLAY "Staff member's last name: " staff-last-name END-IF END-PERFORM EXEC SQL CLOSE C1 END-EXEC IF SQLCODE NOT = ZERO DISPLAY 'Error: Could not close cursor.' DISPLAY SQLERRMC DISPLAY SQLERRML END-IF
The failure occurs because the COBOL compiler, when possible, compiles 01-level fields and their subordinate 01-level FILLER fields as JVM types.
To ensure successful compilation, use traditional COBOL data types, such as PIC X(n), COMP-3, etc., for host variables rather than object types, such as string, binary-long, BigDecimal, etc., and do one of the following:
This scenario does not apply to stored procedures called using the CALL statement.