sql – 如何处理表或视图不存在异常？

2023年3月17日 338次阅读

我有一组表名,比方说150.每个表都有mail_id列,现在我想在所有表中搜索一个mail_id.为此我写了一个Plsql块.当我遍历表集时,一些表不存在,因此它引发异常.我有异常处理块来处理该异常.现在我想循环整个表,即使它引发异常？任何的想法？实际上我的块没有处理那个特殊的异常！

declare
my_mail_id varchar2(50):='xyaksj@jsm.com';
tmp_table varchar2(125);
type varchar_collector is table of varchar2(255);
var varchar_collector;
table_does_not_exist exception;  
PRAGMA EXCEPTION_INIT(table_does_not_exist, -00942);

begin

for cntr in (select table_name from user_tables)
    loop

    tmp_table:=cntr.table_name;
    dbms_output.put_line(tmp_table);
        for mail in (select email_address from tmp_table where lower(email_address) like '%my_mail_id%' )
        loop
            dbms_output.put_line(tmp_table);
        end loop;
    end loop;

    exception 
    when no_data_found then 
        dbms_output.put_line('email address not found');

    WHEN table_does_not_exist then 
         dbms_output.put_line('table dose not exists');

    WHEN OTHERS THEN
    --raise_application_error(-20101, 'Expecting at least 1000 tables');
    IF (SQLCODE = -942) THEN
        --DBMS_Output.Put_Line (SQLERRM);
        DBMS_Output.Put_Line ('in exception');--this exception not handled
    ELSE
        RAISE;
    END IF;
end;

最佳答案 只需在循环内的匿名块中处理异常.

DECLARE
  my_mail_id VARCHAR2(50) := 'xyaksj@jsm.com';
  tmp_table  VARCHAR2(125);
  TYPE varchar_collector IS TABLE OF VARCHAR2(255);
  var varchar_collector;
  table_does_not_exist EXCEPTION;
  PRAGMA EXCEPTION_INIT(table_does_not_exist, -00942);

BEGIN

  FOR cntr IN (SELECT table_name FROM user_tables)
  LOOP
    BEGIN
      tmp_table := cntr.table_name;
      dbms_output.put_line(tmp_table);
      FOR mail IN (SELECT email_address
                     FROM tmp_table
                    WHERE lower(email_address) LIKE '%my_mail_id%')
      LOOP
        dbms_output.put_line(tmp_table);
      END LOOP;

    EXCEPTION
      WHEN no_data_found THEN
        dbms_output.put_line('email address not found');

      WHEN table_does_not_exist THEN
        dbms_output.put_line('table dose not exists');

      WHEN OTHERS THEN
        --raise_application_error(-20101, 'Expecting at least 1000 tables');
        IF (SQLCODE = -942)
        THEN
          --DBMS_Output.Put_Line (SQLERRM);
          DBMS_Output.Put_Line('in exception'); --this exception not handled
        ELSE
          RAISE;
        END IF;
    END;
  END LOOP;
END;
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