Mysql 在SQL中搜索数据_Mysql_Sql

Mysql 在SQL中搜索数据

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Mysql 在SQL中搜索数据,mysql,sql,Mysql,Sql,请看下表：我正在构建一个搜索引擎，根据对类别id和值id的搜索，返回卡id值为了更好地解释搜索机制，假设我们试图通过提供汽车在每个类别（category\u id）中应该包含哪些部分（value\u id）的信息来查找汽车（category\u id）例如，我们可能想找到一辆汽车（card\u id），其中类别“燃料类型”（category\u id）的值为“柴油”（value\u id），类别“变速箱”（category\u id）的值为“手动”（value\u id）我的问题是，我

请看下表：

我正在构建一个搜索引擎，根据对

类别id

和

值id

的搜索，返回

卡id

值

为了更好地解释搜索机制，假设我们试图通过提供汽车在每个类别（

category\u id

）中应该包含哪些部分（

value\u id

）的信息来查找汽车（

category\u id

）

例如，我们可能想找到一辆汽车（

card\u id

），其中类别“燃料类型”（

category\u id

）的值为“柴油”（

value\u id

），类别“变速箱”（

category\u id

）的值为“手动”（

value\u id

）

我的问题是，我的知识不足以构建一个查询，该查询将返回

card\u id

s，其中包含多对

category\u id

和

value\u id

例如，如果我想搜索一辆装有柴油发动机的汽车，我可以构建如下查询：

从类别id=1、值id=2的汽车中选择卡片id

其中，

category_id=1

为“燃料类型”类别，

value_id=2

为“柴油”

我的问题是，如何构建一个查询来查找更多的类别-值对？例如，我想寻找配备手动变速箱的柴油车

任何帮助都将不胜感激。提前感谢。

您可以使用聚合和

have

子句来完成此操作：

SELECT card_id
FROM cars
GROUP BY card_id
HAVING SUM(category_id = 1 AND value_id = 2) > 0 AND
       SUM(category_id = 3 and value_id = 43) > 0;

having

子句中的每个条件统计与给定条件匹配的行数。您可以添加任意数量的条件。例如，第一个表示至少有一行的类别为1，值为2

您可以使用聚合和具有子句的

来执行此操作：
SELECT card_id
FROM cars
GROUP BY card_id
HAVING SUM(category_id = 1 AND value_id = 2) > 0 AND
       SUM(category_id = 3 and value_id = 43) > 0;

having
子句中的每个条件统计与给定条件匹配的行数。您可以添加任意数量的条件。例如，第一个表示至少有一行的类别为1，值为2
您可以使用聚合和具有

子句的

来执行此操作：
SELECT card_id
FROM cars
GROUP BY card_id
HAVING SUM(category_id = 1 AND value_id = 2) > 0 AND
       SUM(category_id = 3 and value_id = 43) > 0;

having
子句中的每个条件统计与给定条件匹配的行数。您可以添加任意数量的条件。例如，第一个表示至少有一行的类别为1，值为2
您可以使用聚合和具有

子句的

来执行此操作：
SELECT card_id
FROM cars
GROUP BY card_id
HAVING SUM(category_id = 1 AND value_id = 2) > 0 AND
       SUM(category_id = 3 and value_id = 43) > 0;

having
子句中的每个条件统计与给定条件匹配的行数。您可以添加任意数量的条件。例如，第一个表示至少有一行的类别为1，值为2
另一种方法是创建一个用户定义的函数，该函数接受一个属性/值对表，并返回一个匹配汽车表。这样做的优点是允许任意数量的属性/值对，而无需使用动态SQL
--Declare a "sample" table for proof of concept, replace this with your real data table
DECLARE @T TABLE(PID int, Attr Int, Val int)
--Populate the data table
INSERT INTO @T(PID , Attr , Val) VALUES (1,1,1), (1,3,5),(1,7,9),(2,1,2),(2,3,5),(2,7,9),(3,1,1),(3,3,5), (3,7,9)

--Declare this as a User Defined Table Type, the function would take this as an input
DECLARE @C TABLE(Attr Int, Val int)
--This would be populated by the code that calls the function
INSERT INTO @C (Attr , Val) VALUES (1,1),(7,9)

--The function (or stored procedure) body begins here
--Get a list of IDs for which there is not a requested attribute that doesn't have a matching value for that ID
SELECT DISTINCT PID 
FROM @T as T 
WHERE NOT EXISTS (SELECT C.ATTR FROM @C as C 
                  WHERE NOT EXISTS (SELECT * FROM @T as I 
                                    WHERE I.Attr = C.Attr and I.Val = C.Val and I.PID = T.PID ))

另一种方法是创建一个用户定义的函数，该函数接受一个属性/值对表，并返回一个匹配汽车表。这样做的优点是允许任意数量的属性/值对，而无需使用动态SQL
--Declare a "sample" table for proof of concept, replace this with your real data table
DECLARE @T TABLE(PID int, Attr Int, Val int)
--Populate the data table
INSERT INTO @T(PID , Attr , Val) VALUES (1,1,1), (1,3,5),(1,7,9),(2,1,2),(2,3,5),(2,7,9),(3,1,1),(3,3,5), (3,7,9)

--Declare this as a User Defined Table Type, the function would take this as an input
DECLARE @C TABLE(Attr Int, Val int)
--This would be populated by the code that calls the function
INSERT INTO @C (Attr , Val) VALUES (1,1),(7,9)

--The function (or stored procedure) body begins here
--Get a list of IDs for which there is not a requested attribute that doesn't have a matching value for that ID
SELECT DISTINCT PID 
FROM @T as T 
WHERE NOT EXISTS (SELECT C.ATTR FROM @C as C 
                  WHERE NOT EXISTS (SELECT * FROM @T as I 
                                    WHERE I.Attr = C.Attr and I.Val = C.Val and I.PID = T.PID ))

另一种方法是创建一个用户定义的函数，该函数接受一个属性/值对表，并返回一个匹配汽车表。这样做的优点是允许任意数量的属性/值对，而无需使用动态SQL
--Declare a "sample" table for proof of concept, replace this with your real data table
DECLARE @T TABLE(PID int, Attr Int, Val int)
--Populate the data table
INSERT INTO @T(PID , Attr , Val) VALUES (1,1,1), (1,3,5),(1,7,9),(2,1,2),(2,3,5),(2,7,9),(3,1,1),(3,3,5), (3,7,9)

--Declare this as a User Defined Table Type, the function would take this as an input
DECLARE @C TABLE(Attr Int, Val int)
--This would be populated by the code that calls the function
INSERT INTO @C (Attr , Val) VALUES (1,1),(7,9)

--The function (or stored procedure) body begins here
--Get a list of IDs for which there is not a requested attribute that doesn't have a matching value for that ID
SELECT DISTINCT PID 
FROM @T as T 
WHERE NOT EXISTS (SELECT C.ATTR FROM @C as C 
                  WHERE NOT EXISTS (SELECT * FROM @T as I 
                                    WHERE I.Attr = C.Attr and I.Val = C.Val and I.PID = T.PID ))

另一种方法是创建一个用户定义的函数，该函数接受一个属性/值对表，并返回一个匹配汽车表。这样做的优点是允许任意数量的属性/值对，而无需使用动态SQL
--Declare a "sample" table for proof of concept, replace this with your real data table
DECLARE @T TABLE(PID int, Attr Int, Val int)
--Populate the data table
INSERT INTO @T(PID , Attr , Val) VALUES (1,1,1), (1,3,5),(1,7,9),(2,1,2),(2,3,5),(2,7,9),(3,1,1),(3,3,5), (3,7,9)

--Declare this as a User Defined Table Type, the function would take this as an input
DECLARE @C TABLE(Attr Int, Val int)
--This would be populated by the code that calls the function
INSERT INTO @C (Attr , Val) VALUES (1,1),(7,9)

--The function (or stored procedure) body begins here
--Get a list of IDs for which there is not a requested attribute that doesn't have a matching value for that ID
SELECT DISTINCT PID 
FROM @T as T 
WHERE NOT EXISTS (SELECT C.ATTR FROM @C as C 
                  WHERE NOT EXISTS (SELECT * FROM @T as I 
                                    WHERE I.Attr = C.Attr and I.Val = C.Val and I.PID = T.PID ))

您的解决方案按预期工作。感谢您的代码和解释，以及您的时间。您的解决方案按预期工作。感谢您的代码和解释，以及您的时间。您的解决方案按预期工作。感谢您的代码和解释，以及您的时间。您的解决方案按预期工作。感谢您的代码和解释，以及您的时间。