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POHow to make this query run faster?
 

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  1. POHow to make this query run faster?
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    <p>I have query like this:</p> <pre><code> SELECT `om_chapter`.`manganame` as `link`, (SELECT `manganame` FROM `om_manga` WHERE `Active` = '1' AND `om_manga`.`link` = `om_chapter`.`manganame` LIMIT 0,1) AS `manganame`, (SELECT `cover` FROM `om_manga` WHERE `Active` = '1' AND `om_manga`.`link` = `om_chapter`.`manganame` LIMIT 0,1) AS `cover`, (SELECT `othername` FROM `om_manga` WHERE `Active` = '1' AND `om_manga`.`link` = `om_chapter`.`manganame` LIMIT 0,1) AS `othername` FROM `om_chapter` WHERE `Active` = '1' AND (SELECT `Active` From `om_manga` WHERE `om_manga`.`link` = `om_chapter`.`manganame` LIMIT 0,1) AND `id` IN ( SELECT MAX(`id`) FROM `om_chapter` WHERE `Active` = '1' GROUP BY `manganame` ) ORDER BY `id` DESC LIMIT 10 </code></pre> <p>So how can I make this query faster?</p> <p>Here are my tables:</p> <p>om_chapter:</p> <pre><code>id | manganame | chapter | Active ----------------------------------------- 1 | naruto | 1 | 1 2 | naruto | 12 | 1 3 | naruto | 22 | 1 4 | bleach | 10 | 1 5 | bleach | 15 | 1 6 | gents | 1 | 1 7 | naruto | 21 | 1 </code></pre> <p>om_manga:</p> <pre><code>id | othername | manganame | cover | Active ----------------------------------------------------- 1 | naruto | naruto | n.jpg | 1 2 | bleach | bleach | b.jpg | 1 4 | gents | gents | g.jpg | 1 </code></pre> <p>First thing i want form this query is to give me 10 last rows form om_chapter by grouping manganame and ordering by id.. i try to use a simple query by using group or even distinct but none of them give me the right result... </p> <p>In a simple query with group or distinct, the result is like this:</p> <pre><code>id | manganame | chapter | Active ----------------------------------------- 7 | prince | 21 | 1 5 | gent | 15 | 1 2 | naruto | 12 | 1 1 | bleach | 1 | 1 </code></pre> <p>But i want this result: </p> <pre><code>id | manganame | chapter | Active ----------------------------------------- 9 | gents | 21 | 1 8 | bleach | 21 | 1 7 | prince | 21 | 1 6 | naruto | 1 | 1 </code></pre> <p>So i use this:</p> <pre><code>WHERE `Active` = '1' AND (SELECT `Active` From `om_manga` WHERE `om_manga`.`link` = `om_chapter`.`manganame` LIMIT 0,1) AND `id` IN ( SELECT MAX(`id`) FROM `om_chapter` WHERE `Active` = '1' GROUP BY `manganame` ) </code></pre> <p>And i use sub select in where because i want Active's field in om_manga's table be 1..</p> <p>For the reset of sub select, i actually didn`t try join, but i will..!</p>
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      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USkamal
    1. USkamal
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    1. PO
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    1. VO
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      1. POHow to make this query run faster?
      1. This table or related slice is empty.
      1. VTDownMod
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      1. POHow to make this query run faster?
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      1. VTUpMod
    1. COPosting additional information about the table structures will help. Like indices etc.
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      1. POHow to make this query run faster?
      1. USdanielrsmith
    2. COWow. That's about eighty times more complicated than it needs to be. I don't have time to try and figure out what you're trying to accomplish, but you should look into JOIN statements (I think you want an INNER JOIN for this...). Basically, it will join together two tables and you can set the conditions for the join. I think it's faster than subqueries for the most part.
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      1. POHow to make this query run faster?
      1. USJemaclus
    3. CO@kamal That query is almost certainly more complicated than need be, but it's difficult to offer a better solution without knowing *what you're trying to achieve*. What output should this query produce? Specifically, are you looking for results for each chapter of each manga, or just the highest-numbered chapter?
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      1. POHow to make this query run faster?
      1. USDan J
 

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