The EXECUTE IMMEDIATE statement:
EXECUTE IMMEDIATE combines the basic functions of the PREPARE and EXECUTE statements. It can be used to prepare and execute SQL statements that contain neither variables nor parameter markers.
This statement can only be embedded in an application program, SQL function, SQL procedure, or trigger. It is an executable statement that cannot be dynamically prepared. It must not be specified in Java™.
The authorization rules are those defined for the SQL statement specified by EXECUTE IMMEDIATE. For example, see INSERT for the authorization rules that apply when an INSERT statement is executed using EXECUTE IMMEDIATE.
The authorization ID of the statement is the run-time authorization ID unless DYNUSRPRF(*OWNER) was specified on the CRTSQLxxx command when the program was created. For more information, see Authorization IDs and authorization names.
>>-EXECUTE IMMEDIATE--+-variable----------+-------------------->< '-string-expression-'
The value of the identified variable or string expression is called a statement string.
The statement string must be one of the following SQL statements:70
ALTER | INSERT | SET CURRENT DEBUG MODE |
CALL | LABEL | SET CURRENT DEGREE |
COMMENT | LOCK TABLE | SET ENCRYPTION PASSWORD |
COMMIT | REFRESH TABLE | SET PATH |
CREATE | RELEASE SAVEPOINT | SET SCHEMA |
DECLARE GLOBAL TEMPORARY TABLE | RENAME | SET SESSION AUTHORIZATION |
DELETE | REVOKE | SET TRANSACTION |
DROP | ROLLBACK | UPDATE |
GRANT | SAVEPOINT |
The statement string must not:
When an EXECUTE IMMEDIATE statement is executed, the specified statement string is parsed and checked for errors. If the SQL statement is not valid, it is not executed and the error condition that prevents its execution is reported in the stand-alone SQLSTATE and SQLCODE. If the SQL statement is valid, but an error occurs during its execution, that error condition is reported in the stand-alone SQLSTATE and SQLCODE. Additional information on the error can be retrieved from the SQL Diagnostics Area (or the SQLCA).
If the same SQL statement is to be executed more than once, it is more efficient to use the PREPARE and EXECUTE statements rather than the EXECUTE IMMEDIATE statement.
Use C to execute the SQL statement in the variable Qstring.
void main () { EXEC SQL BEGIN DECLARE SECTION END-EXEC. char Qstring[100] = "INSERT INTO WORK_TABLE SELECT * FROM EMPPROJACT WHERE ACTNO >= 100"; EXEC SQL END DECLARE SECTION END-EXEC. EXEC SQL INCLUDE SQLCA; . . . EXEC SQL EXECUTE IMMEDIATE :Qstring; return; }