From 9i，you can using the system event ORA_SQL_TXT to get the SQL by Trigger.
SQL> CREATE TABLE T (ID NUMBER, NAME VARCHAR2(30));
SQL> CREATE TABLE T_LOG (EXECUTE_DATE DATE, SQL_STATMENT CLOB);
SQL> CREATE OR REPLACE TRIGGER T
2 BEFORE INSERT OR UPDATE OR DELETE ON T
3 FOR EACH ROW
4 DECLARE
5 V_SQL_OUT ORA_NAME_LIST_T;
6 V_NUM NUMBER;
7 V_SQL_STATMENT VARCHAR2(32767);
8 BEGIN
9 V_NUM := ORA_SQL_TXT(V_SQL_OUT);
10 FOR I IN 1 .. V_NUM LOOP
11 V_SQL_STATMENT := V_SQL_STATMENT || V_SQL_OUT(I);
12 END LOOP;
13 INSERT INTO T_LOG (EXECUTE_DATE, SQL_STATMENT)
14 VALUES (SYSDATE, V_SQL_STATMENT);
15 END;
16 /
SQL> INSERT INTO T VALUES (1, 'A');
SQL> INSERT INTO T (ID) VALUES (2);
SQL> UPDATE T SET NAME = 'B' WHERE ID = 2;
SQL> DELETE T;
SQL> ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS';
SQL> SELECT * FROM T_LOG;
EXECUTE_DATE SQL_STATMENT
------------------- -----------------------------------------------
2007-09-13 22:55:35 INSERT INTO T VALUES (1, 'A')
2007-09-13 22:55:46 INSERT INTO T (ID) VALUES (2)
2007-09-13 22:55:54 UPDATE T SET NAME = 'B' WHERE ID = 2
2007-09-13 22:56:00 DELETE T
2007-09-13 22:56:00 DELETE T
After 9206，Oracle no more support this function in trigger for DML.just only support in system event.
--DML触发器中使用ORA_SQL_TXT函数，这个函数返回NULL，而且传入的OUT变量将不会被初始化。
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