經常給領導查資料，但是資料庫不少表是分表的，查詢起來貼上複製很麻煩，這裡僅作記錄，之前已經介紹過Mysql儲存過程的使用，和變數宣告，以及分支判斷等。

mysql 儲存過程簡單使用 ：https://www.cnblogs.com/jefferyfeng/p/14479399.html

/**
 * 生成分表查詢語句
 * sqls：原始sql，帶有佔位符
 * tableNums: 分表個數
 * skipType: 跳過分表型別 0.不跳過 1.跳過奇數表 2.跳過偶數表
 * replaceStr: 替換佔位符
 *
 * @date 2021-11-08
 * @author fdh
 */
CREATE
 
 DEFINER=`root`@`%` FUNCTION `buildSql`(sqls varchar(1000), tableNums int(3), skipType int(1), replaceStr varchar(100)) RETURNS text CHARSET utf8
BEGIN
  set @oriSql = sqls;
    set @oriReplaceStr = replaceStr;
    set @i = 0;
    set @tempSql = '';
    set @replaceSql = '';
    -- 迴圈開始
    while @i<tableNums DO 
    
        
 
if (skipType = 1 and mod(@i, 2) = 0) then 
            set @replaceSql := replace(@oriSql, @oriReplaceStr, @i);
        elseif (skipType = 2 and mod(@i, 2) = 1) then 
            set @replaceSql := replace(@oriSql, @oriReplaceStr, @i);
        end if;
        
        if (skipType = 0 and @replaceSql =
 
 '') then
                set @replaceSql := replace(@oriSql, @oriReplaceStr, @i);
        end if;
        
      if (@tempSql = '' and @replaceSql != '') then 
            set @tempSql := CONCAT(@replaceSql, '\n');
        elseif (@tempSql != '' and @replaceSql != '') then
            set @tempSql := CONCAT(@tempSql, 'union all\n', @replaceSql, '\n');
        end if;
        
        -- 重置
        set @i := @i + 1;
        set @replaceSql := '';
    end while; 
    -- 迴圈結束
    RETURN @tempSql;
END

使用示例：

select buildSql("select DATE_FORMAT(create_time, '%Y-%m') as months, count(1) as counts from crm_clue_call_record*prefix* where create_time > '2021-11-01 00:00:00' and create_time < '2021-11-08 00:00:00' group by DATE_FORMAT(create_time, '%Y-%m')", 32, 2, "*prefix*");