X Oracle drop if exists

參考https://stackoverflow.com/questions/1799128/oracle-if-table-exists

我的官方博客http://blog.alei.tech ，轉載請注明。網頁地址https://alei.tech/2016/08/12/%E5%9C%A8Oracle%E6%95%B0%E6%8D%AE%E4%B8%AD%E5%AF%BB%E6%89%BE%E4%B8%80%E4%B8%AA%E5%80%BC/

場景
刪除表，視圖等對象時，靜默執行，不返回報錯信息
類似dorp table if exists，語句可反復執行
開發人員編寫sql，讓實施人員執行
直接寫drop table abc，如果abc表已經被刪除或者不存在，返回報錯信息，對於不懂sql的實施人員來說，會產生干擾

代碼示例
創建存儲過程
適用於drop table, procedure, function, trigger, view, sequence

create or replace procedure dropObject(ObjName varchar2,ObjType varchar2)
is
 v_counter number := 0;   
begin    
  if upper(ObjType) = 'TABLE' then
    select count(*) into v_counter from user_tables where table_name = upper(ObjName);
    if v_counter > 0 then          
      execute immediate 'drop table ' || ObjName || ' cascade constraints';        
    end if;   
  end if;
  if upper(ObjType) = 'PROCEDURE' then
    select count(*) into v_counter from User_Objects where object_type = 'PROCEDURE' and OBJECT_NAME = upper(ObjName);
      if v_counter > 0 then          
        execute immediate 'DROP PROCEDURE ' || ObjName;        
      end if; 
  end if;
  if upper(ObjType) = 'FUNCTION' then
    select count(*) into v_counter from User_Objects where object_type = 'FUNCTION' and OBJECT_NAME = upper(ObjName);
      if v_counter > 0 then          
        execute immediate 'DROP FUNCTION ' || ObjName;        
      end if; 
  end if;
  if upper(ObjType) = 'TRIGGER' then
    select count(*) into v_counter from User_Triggers where TRIGGER_NAME = upper(ObjName);
      if v_counter > 0 then          
        execute immediate 'DROP TRIGGER ' || ObjName;
      end if; 
  end if;
  if upper(ObjType) = 'VIEW' then
    select count(*) into v_counter from User_Views where VIEW_NAME = upper(ObjName);
      if v_counter > 0 then          
        execute immediate 'DROP VIEW ' || ObjName;        
      end if; 
  end if;
  if upper(ObjType) = 'SEQUENCE' then
    select count(*) into v_counter from user_sequences where sequence_name = upper(ObjName);
      if v_counter > 0 then          
        execute immediate 'DROP SEQUENCE ' || ObjName;        
      end if; 
  end if;
end;

使用存儲過程
創建temp_table表之前，判斷，if exists then drop


此語句示例在pl/sql developer中執行
”/”必須在行首，之前不能有空格
begin
  dropObject('temp_table','table');
end;
/
create table

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版權聲明：本文為CSDN博主「lemon_shenzhen」的原創文章，遵循CC 4.0 BY-SA版權協議，轉載請附上原文出處鏈接及本聲明。
原文鏈接：https://blog.csdn.net/lemon_shenzhen/article/details/79022882