求查询优化方法
程序员文章站
2022-06-10 19:38:03
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请问下面的代码有优化的方法吗
改写成方法
请问再加两个条件怎么加啊,我这样加了,但这样加了和数据库对不上,少了很多条数据。
$catalog_1 = "select name from commodity where catalog = 1 ORDER BY rank desc LIMIT 10";$result_1 = mysql_query($catalog_1);while($row_1 = mysql_fetch_assoc($result_1)){ $response [] = $row_1;}$catalog_2 = "select name from commodity where catalog = 2 ORDER BY rank desc LIMIT 10";$result_2 = mysql_query($catalog_2);while($row_2 = mysql_fetch_assoc($result_2)){ $response [] = $row_2;}$catalog_3 = "select name from commodity where catalog = 3 ORDER BY rank desc LIMIT 10";$result_3 = mysql_query($catalog_3);while($row_3 = mysql_fetch_assoc($result_3)){ $response [] = $row_3;}$catalog_4 = "select name from commodity where catalog = 4 ORDER BY rank desc LIMIT 10";$result_4 = mysql_query($catalog_4);while($row_4 = mysql_fetch_assoc($result_4)){ $response [] = $row_4;}$catalog_5 = "select name from commodity where catalog = 5 ORDER BY rank desc LIMIT 10";$result_5 = mysql_query($catalog_5);while($row_5 = mysql_fetch_assoc($result_5)){ $response [] = $row_5;}$catalog_6 = "select name from commodity where catalog = 6 ORDER BY rank desc LIMIT 10";$result_6 = mysql_query($catalog_6);while($row_6 = mysql_fetch_assoc($result_6)){ $response [] = $row_6;}$catalog_7 = "select name from commodity where catalog = 7 ORDER BY rank desc LIMIT 10";$result_7 = mysql_query($catalog_7);while($row_7 = mysql_fetch_assoc($result_7)){ $response [] = $row_7;}$catalog_8 = "select name from commodity where catalog = 8 ORDER BY rank desc LIMIT 10";$result_8 = mysql_query($catalog_8);while($row_8 = mysql_fetch_assoc($result_8)){ $response [] = $row_8;}$catalog_11 = "select name from commodity where catalog = 11 ORDER BY rank desc LIMIT 10";$result_11 = mysql_query($catalog_11);while($row_11 = mysql_fetch_assoc($result_11)){ $response [] = $row_11;}$catalog_10 = "select name from commodity where catalog = 10 ORDER BY rank desc LIMIT 10";$result_10 = mysql_query($catalog_10);while($row_10 = mysql_fetch_assoc($result_10)){ $response [] = $row_10;}
回复讨论(解决方案)
function getCataLog($catalog){ $catalog = "select name from commodity where catalog = ".$catalog." ORDER BY rank desc LIMIT 10"; $result = mysql_query($catalog); while($row = mysql_fetch_assoc($result)){ $response [] = $row; }}
改写成方法
是这样调用吗 getCataLog(11);
但没数据出来
是这样调用吗 getCataLog(11);
但没数据出来
function getCataLog($catalog){ $catalog = "select name from commodity where catalog = ".$catalog." ORDER BY rank desc LIMIT 10"; $result = mysql_query($catalog); while($row = mysql_fetch_assoc($result)){ $response [] = $row; } return $response;}
还有个神奇的问题
catalog = 11 数据库有3条记录
catalog = 12 数据库有11条记录
$responses = getCataLog(11) + getCataLog(12);
这样输出应该是有14条记录的,但实标只输出了10条。而且catalog = 12的数据是从第四条开始接的
不是这么用的 php里面的 + 相比于数组的合并 array_merge 相同键值的被覆盖掉了
select name,catalog,rank from commodity c where 10 > (select count(*) from commodity where catalog=c.catalog and id>c.id) and catalog in (1,2,3,4,5,6,7,8,10,11) order by c.catalog,c.rank desc
function getCataLog($catalog,&$response = array()){ $catalog = "select name from commodity where catalog = ".$catalog." ORDER BY rank desc LIMIT 10"; $result = mysql_query($catalog); while($row = mysql_fetch_assoc($result)){ $response [] = $row; }}$response = array();getCataLog(1,$response);var_dump($response);getCataLog(2,$response);var_dump($response);
select name,catalog,rank from commodity c where 10 > (select count(*) from commodity where catalog=c.catalog and id>c.id) and catalog in (1,2,3,4,5,6,7,8,10,11) order by c.catalog,c.rank desc
请问再加两个条件怎么加啊,我这样加了,但这样加了和数据库对不上,少了很多条数据。
$marketId = $_GET['marketId'];$cityId = $_GET['cityId'];"select name from commodity where catalog = 1 and cityId = $cityId and marketId = $marketId ORDER BY rank desc LIMIT 10""select name,catalog,rank from commodity c where 10 > (select count(*) from commodity where catalog=c.catalog and id>c.id) and catalog in (1,2,3,4,5,6,7,8,10,11) and cityId = $cityId and marketId = $marketId order by c.catalog,c.rank desc"
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