如何捕捉执行立即（开放）的错误？

Question

我有这个程序：

PROCEDURE proc_with_cursor(  P_PARAM1_IN NUMBER, P_PARAM2_IN NUMBER, P_CURSOR_OUT OUT SYS_REFCURSOR)
    IS
    v_sql   VARCHAR2 (32767);
    v_script   VARCHAR2 (32767);
    v_bind_vars VARCHAR2 (32767);
BEGIN
     v_sql := 'BEGIN OPEN :1 FOR :2 ';
     v_bind_vars := P_PARAM1_IN||', '||P_PARAM2_IN;
     v_sql := v_sql||' USING '||v_bind_vars||'; ';
    --tried also following  but also couldn't catch the error!
    --v_sql := v_sql ||'EXCEPTION WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE(''error: ''||SQLCODE||'' - ''||SQLERRM); END;';
    v_sql := v_sql||' END;';

    v_script := 'select sysdate from dual where 1= :bind_first and 2 = :bindsecond';

    EXECUTE IMMEDIATE v_sql using P_CURSOR_OUT, v_script;     

    EXCEPTION 
    WHEN OTHERS THEN 
        DBMS_OUTPUT.PUT_LINE('error: '||SQLCODE||' - '||SQLERRM); -- this part is not catching the error!!!!!   
END;

有时，脚本会抛出如下错误：

ORA-12847：由于并发 DDL 操作重试解析

[错误] 执行 (1:1): ORA-12847: 由于并发 DDL 操作重试解析

我的问题是：如何捕获该错误？

Answer 1

我不明白你的问题。如果你有这个程序

CREATE OR REPLACE PROCEDURE proc_with_cursor(  p_param1_in NUMBER, p_param2_in NUMBER, p_cursor_out OUT SYS_REFCURSOR)
IS
    v_script   VARCHAR2 (32767);
BEGIN
    v_script := 'select sysdate fromM dual where 1= :bind_first and 2 = :bindsecond';
    OPEN p_cursor_out FOR v_script USING p_param1_in, p_param2_in;
END;

然后你得到这个：

DECLARE
    cur SYS_REFCURSOR;
BEGIN
    proc_with_cursor(1, 2, cur);    
end;
/

Error at line 1
ORA-00923: FROM keyword not found where expected
ORA-06512: at "xxx.PROC_WITH_CURSOR", line 6
ORA-06512: at line 4

您还想得到什么？您的（糟糕的）代码正在运行：

CREATE OR REPLACE PROCEDURE proc_with_cursor(  P_PARAM1_IN NUMBER, P_PARAM2_IN NUMBER, P_CURSOR_OUT OUT SYS_REFCURSOR) IS
    v_sql   VARCHAR2 (32767);
    v_script   VARCHAR2 (32767);
    v_bind_vars VARCHAR2 (32767);
BEGIN
    v_sql := 'BEGIN OPEN :1 FOR :2 ';
    v_bind_vars := P_PARAM1_IN||', '||P_PARAM2_IN;
    v_sql := v_sql||' USING '||v_bind_vars||'; ';
    v_sql := v_sql||' END;';

    v_script := 'select sysdate fromm dual where 1= :bind_first and 2 = :bindsecond';

    EXECUTE IMMEDIATE v_sql USING P_CURSOR_OUT, v_script;     

EXCEPTION 
    WHEN OTHERS THEN 
        DBMS_OUTPUT.PUT_LINE('error: '||SQLCODE||' - '||SQLERRM);   
END;


DECLARE
    cur SYS_REFCURSOR;
BEGIN
    proc_with_cursor(1,2, cur);
END;

在 DBMS_OUTPUT 上打印 error: -923 - ORA-00923: FROM keyword not found where expected。

如果你想获得例外，那么做

CREATE OR REPLACE PROCEDURE proc_with_cursor(  P_PARAM1_IN NUMBER, P_PARAM2_IN NUMBER, P_CURSOR_OUT OUT SYS_REFCURSOR) IS
    v_sql   VARCHAR2 (32767);
    v_script   VARCHAR2 (32767);
    v_bind_vars VARCHAR2 (32767);
BEGIN
    ...    
    EXECUTE IMMEDIATE v_sql USING P_CURSOR_OUT, v_script;     

EXCEPTION 
    WHEN OTHERS THEN 
        DBMS_OUTPUT.PUT_LINE('error: '||SQLCODE||' - '||SQLERRM);  
        RAISE;  
END;

Answer 2

您不能将对象 names（例如游标名称）和变量 names 绑定到动态 SQL，只能绑定 values。我认为这可能会达到您的预期：

PROCEDURE proc_with_cursor(  p_param1_in NUMBER, p_param2_in NUMBER, p_cursor_out OUT SYS_REFCURSOR)
IS
    v_script   VARCHAR2 (32767);
BEGIN
    v_script := 'select sysdate from dual where 1= :bind_first and 2 = :bindsecond';

    OPEN p_cursor_out FOR v_script USING p_param1_in, p_param2_in;

EXCEPTION
    WHEN OTHERS THEN
        dbms_output.put_line('error: '||sqlcode||' - '||sqlerrm); 
END;