Question

请帮帮我，如何加快这个SQL查询？

SELECT pa.*
FROM ParametrickeVyhladavanie pa, 
     (SELECT p.*
     FROM produkty p
     WHERE p.KATEGORIA IN ('$categoryArray')) produkt
WHERE produkt.ATTRIBUTE_CODE LIKE CONCAT('%', pa.code, '%')
AND produkt.ATTRIBUTE_VALUE LIKE CONCAT('%', pa.ValueCode, '%')
GROUP BY pa.code

索引： pa.code，pa.ValueCode，p.ATTRIBUTE_CODE，p.ATTRIBUTE_VALUE

显示0到25行（总共26行，查询 20.4995秒）

修改实际代码：

SELECT pa.*
FROM ParametrickeVyhladavanie pa
WHERE EXISTS
(
   SELECT 1 FROM produkty p
   JOIN 
   PRODUCT_INFO AS pi
   ON p.ProId = pi.ProduktID
   AND p.KATEGORIA IN ('Mobily'))

AND pi.ATTRIBUTE_CODE = pa.AttributeCode
AND pi.ATTRIBUTE_VALUE = pa.ValueCode
GROUP BY pa.code

此代码显示错误#1054 - Unknown column 'pi.ATTRIBUTE_CODE' in 'where clause' pi.表仅在(和)

之间有效

编辑 - 这是答案

我将MySQL 5.1更改为MariaDB 5.5，速度更快!!!

Answer 1

不幸的是，您的数据库设计迫使性能降低。

这将解决您的性能问题：您应该创建一个新表（PRODUCT_INFO）并使外键指向produkty的主键。使用ATTRIBUTE_CODE和ATTRIBUTE_VALUE中的各个值填充此表。

SELECT pa.code
FROM ParametrickeVyhladavanie pa
WHERE EXISTS
(
SELECT 1 FROM produkty p
JOIN 
PRODUCT_INFO AS pi
ON    p.ProId = pi.ProduktID
WHERE pi.ATTRIBUTE_CODE = pa.Code
AND pi.ATTRIBUTE_VALUE = pa.ValueCode
AND p.KATEGORIA IN ('Mobily'))
GROUP BY pa.code

Answer 2

您可以尝试直接加入produkty：

SELECT pa.*
FROM ParametrickeVyhladavanie pa
JOIN produkty p
  ON p.ATTRIBUTE_CODE LIKE CONCAT('%', pa.code, '%')
 AND p.ATTRIBUTE_VALUE LIKE CONCAT('%', pa.ValueCode, '%')
 AND p.KATEGORIA IN ('$categoryArray')
GROUP BY pa.code

Answer 3

试试这个 -

SELECT *
FROM (
    SELECT DISTINCT Code, ValueCode
    FROM ParametrickeVyhladavanie
) AS t
WHERE EXISTS(
    SELECT 1
    FROM produkty
    WHERE KATEGORIA IN ('$categoryArray')
        AND ATTRIBUTE_CODE LIKE CONCAT('%', t.code, '%')
        AND ATTRIBUTE_VALUE LIKE CONCAT('%', t.ValueCode, '%')
)

Answer 4

这是怎么回事？使用convert而不是concat

SELECT pa.*
FROM ParametrickeVyhladavanie pa
JOIN produkty p
ON p.ATTRIBUTE_CODE LIKE CONVERT(NVARCHAR,'%')+ pa.code + CONVERT(NVARCHAR,'%')
AND p.ATTRIBUTE_VALUE LIKE CONVERT(NVARCHAR,'%')+ pa.ValueCode+CONVERT(NVARCHAR,'%')
AND p.KATEGORIA IN ('$categoryArray')
GROUP BY pa.code

如何从2个表中选择提高SQL查询的性能

4 个答案: