Oracle：如何在异常处理后继续执行

Question

我正在编写一个脚本来执行多个唯一查询（不能放在循环中）。添加异常处理程序时，一旦发生第一个错误，便会处理异常，但编译器会退出该块并终止程序。

我想了解，编译器如何处理异常并继续执行下一个查询。

下面是我一直在使用的代码：

DECLARE
  NEW_VAR1 VARCHAR2(20000);
  table_does_not_exist exception;
  PRAGMA EXCEPTION_INIT(table_does_not_exist, -942);
BEGIN
  DBMS_output.put_line('Query 1 Execution');
  EXECUTE IMMEDIATE 'BEGIN
    SELECT "defaultpwd" INTO :out1 from sys.user$ where name="APEX_040000" and substr(spare4,3,40)=rawtohex(utl_raw.cast_to_varchar2(sys.dbms_crypto.hash(utl_raw.cast_to_raw("oracle")||hextoraw(substr(spare4,43,20)), 3))) UNION SELECT "defaultpwd" from sys.user$ where name="APEX_040000" and password="EE7785338B8FFE3D";
  END;'
  USING out NEW_VAR1;
  DBMS_output.put_line(NEW_VAR1);

  DBMS_output.put_line('Query 2 Execution');
  EXECUTE IMMEDIATE 'BEGIN
    SELECT "defaultpwd" INTO :out2 from sys.user$ where name="APEX_040000" and substr(spare4,3,40)=rawtohex(utl_raw.cast_to_varchar2(sys.dbms_crypto.hash(utl_raw.cast_to_raw("oracle")||hextoraw(substr(spare4,43,20)), 3))) UNION SELECT "defaultpwd" from sys.user$ where name="APEX_040000" and password="EE7785338B8FFE3D";
  END;'
  USING out NEW_VAR1;
  DBMS_output.put_line(NEW_VAR1);
EXCEPTION
  WHEN table_does_not_exist THEN
    DBMS_output.put_line('Table does not exist!!');
  WHEN others then
    DBMS_output.put_line('Error!!');
END;

在这种情况下，期望的结果是：

Query 1 Execution
Error!!
Query 2 Execution
Error!!

实际结果是：

Query 1 Execution
Error!!

如果上述代码效率不高，我可以选择执行多种不同查询的替代方法。 （我几乎没有几个小时的Oracle开发经验。非常感谢任何有用的资源）。

谢谢！

Answer 1

我认为您需要为每个查询使用不同的异常块。像这样的东西：

    DECLARE
      NEW_VAR1 VARCHAR2(20000);
      table_does_not_exist exception;
      PRAGMA EXCEPTION_INIT(table_does_not_exist, -942);
    BEGIN
      BEGIN
          DBMS_output.put_line('Query 1 Execution');
          EXECUTE IMMEDIATE 'BEGIN
            SELECT "defaultpwd" INTO :out1 from sys.user$ where name="APEX_040000" and    substr(spare4,3,40)=rawtohex(utl_raw.cast_to_varchar2(sys.dbms_crypto.hash(utl_raw.cast_to_raw("oracle")||hextoraw(substr(spare4,43,20)), 3))) UNION SELECT "defaultpwd" from sys.user$ where name="APEX_040000" and password="EE7785338B8FFE3D";
          END;'
          USING out NEW_VAR1;
          DBMS_output.put_line(NEW_VAR1);
      EXCEPTION
          WHEN table_does_not_exist THEN
              DBMS_output.put_line('Table does not exist!!');
          WHEN others then
              DBMS_output.put_line('Error!!');
      END;

      BEGIN
          DBMS_output.put_line('Query 2 Execution');
          EXECUTE IMMEDIATE 'BEGIN
            SELECT "defaultpwd" INTO :out2 from sys.user$ where name="APEX_040000" and substr(spare4,3,40)=rawtohex(utl_raw.cast_to_varchar2(sys.dbms_crypto.hash(utl_raw.cast_to_raw("oracle")||hextoraw(substr(spare4,43,20)), 3))) UNION SELECT "defaultpwd" from sys.user$ where name="APEX_040000" and password="EE7785338B8FFE3D";
          END;'
          USING out NEW_VAR1;
          DBMS_output.put_line(NEW_VAR1);
      EXCEPTION
          WHEN table_does_not_exist THEN
              DBMS_output.put_line('Table does not exist!!');
          WHEN others then
              DBMS_output.put_line('Error!!');
      END;
    END;