Question

I m 试图用文字I.nt做一些问题,在这些问题上,该网址似乎正在填上我的sql <代码>/tmp。页: 1

我检查了<条码>查询记录,并提出了许多问题。

SELECT
    COUNT(*) AS `total`
FROM
    (
        SELECT
                *
        FROM
            `Advertising_Business_and_Retail`
        WHERE
            MATCH (`wm`, `locn`, `gns`) AGAINST( outdoor apparel company )
    UNION
        SELECT
                *
        FROM
            `Chemical` WHERE MATCH (`wm`, `locn`, `gns`) AGAINST( outdoor apparel company )
    UNION
        SELECT
                *
        FROM `Clothing` WHERE MATCH (`wm`, `locn`, `gns`) AGAINST( outdoor apparel company )
    )
AS t;

除我外,我相信45的工会总数(每类表格1次),这些表格是巨大的,但<代码>。广告_Business_and_Retail 表格本身有<代码>450k。

我以人工方式处理这个问题,大约需要2分钟半。

我猜想的是,为什么 /mp正在迅速填补?

对于我能做些什么来解决这个问题,有什么推论?

Answer 1

如果你知道你正在选择的行文中不存在重复,请将<条码>改为<条码>。

此外,还可将<代码>UINON ALL改为简单添加:

select (
  (select count(1) from `Advertising_Business_and_Retail` WHERE MATCH (`wm`, `locn`, `gns`) AGAINST( outdoor apparel company ))
+ (select count(1) from `Chemical` WHERE MATCH (`wm`, `locn`, `gns`) AGAINST( outdoor apparel company ))
+ (select count(1) from `Clothing` WHERE MATCH (`wm`, `locn`, `gns`) AGAINST( outdoor apparel company ))
) as total

Answer 2

这是否越快?

SELECT
    SUM(`count`) AS `total`
FROM
    (
        SELECT
               COUNT(*) AS `count`
        FROM
            `Advertising_Business_and_Retail`
        WHERE
            MATCH (`wm`, `locn`, `gns`) AGAINST( outdoor apparel company )
    UNION
        SELECT
               COUNT(*) AS `count`
        FROM
            `Chemical` WHERE MATCH (`wm`, `locn`, `gns`) AGAINST( outdoor apparel company )
    UNION
        SELECT
                COUNT(*) AS `count`
        FROM `Clothing` WHERE MATCH (`wm`, `locn`, `gns`) AGAINST( outdoor apparel company )
    )
AS t;

友情链接