MySQL-多條件拼接語句

 

BEGIN
SET @baseStr= "SELECT * FROM tbName WHERE 1=1 ";
SET @_where="";
IF 1=1 THEN
　　SET @_where= CONCAT(@_where," AND sourcedomain=\"www.baidu.com\" ");
END IF;

IF 2=2 THEN 
　　SET @_where=CONCAT(@_where," AND userId =4444");
END IF;
  SET @sentence =CONCAT(@baseStr,@_where) ; -- 連接字符串生成要執行的SQL語句
  prepare stmt from @sentence; -- 預編釋一下。 “stmt”預編釋變量的名稱，
  execute stmt; -- 執行SQL語句
  deallocate prepare stmt;    -- 釋放資源
END

 

2.out賦值

SET @_rowCount=0; -- 變量
SET @_count =CONCAT("SELECT COUNT(*) INTO @_rowCount ",@baseStr,@_where);
prepare stmt from @_count;
execute stmt;
deallocate prepare stmt;
SET _pageCount=@_rowCount;