Question

我需要将子项的总和添加到父项。儿童物品＆＃39; childId＆＃39;与父项＆＃39; parentId＆＃39;相同。

在下表中，ParentId＆＃39; 45627＆＃39;总数为0.但是，我需要为11. 11是子项目总数的总和。

+----------+---------+-------+------------+  
| ParentId | ChildId | Name  | TotalCount |  
+----------+---------+-------+------------+  
|    45627 |   12568 | Test1 |          0 |  
|    52678 |   45627 | Test2 |          0 |  
|    23123 |   45627 | Test3 |          7 |  
|    54312 |   45627 | Test4 |          3 |  
|    32123 |   45627 | Test5 |          0 |  
|    12111 |   45627 | Test6 |          1 |  
|    32122 |   45627 | Test7 |          0 |  
|    43123 |   45627 | Test8 |          0 |  
+----------+---------+-------+------------+

预期产出：

+----------+---------+-------+------------+  
| ParentId | ChildId | Name  | TotalCount |  
+----------+---------+-------+------------+  
|    45627 |   12568 | Test1 |         11 |  
|    52678 |   45627 | Test2 |          0 |  
|    23123 |   45627 | Test3 |          7 |  
|    54312 |   45627 | Test4 |          3 |  
|    32123 |   45627 | Test5 |          0 |  
|    12111 |   45627 | Test6 |          1 |  
|    32122 |   45627 | Test7 |          0 |  
|    43123 |   45627 | Test8 |          0 |  
+----------+---------+-------+------------+

虽然能够通过自我加入实现，但性能太慢。

是否有其他方法可以获得更好的预期输出效果。

我试过的查询

SELECT a.parentId
    ,a.childId
    ,out1.TotalCount
FROM test a
LEFT JOIN (
    SELECT a.parentId
        ,sum(b.TotalCount) AS TotalCount
    FROM test a
    INNER JOIN test b ON a.ParentId = b.childId
    GROUP BY a.ParentId
    ) AS out1 ON a.ParentId = out1.ParentId

注意：上表是示例。记录数可以是10,000。

抱歉标记不佳。

Answer 1

如果我正确理解您的需求，这个问题应该符合您的期望：

SELECT x.parentId,
       x.childId,
       CASE WHEN x.total > 0 THEN x.total ELSE x.TotalCount END AS Total
FROM    
   (SELECT a.parentId
          ,a.childId,
          ,a.TotalCount
          ,(SELECT SUM(b.TotalCount) FROM test b WHERE b.childId = a.parentId) AS total
    FROM test a ) x

Answer 2

列名没有意义，输入数据没有意义，（但这是有争议的），并且所需的输出也没有任何意义。这就是为什么这个问题还没有得到任何答案的原因。

假设首先，＆＃34; ParentId＆＃34;已被重命名为＆＃34; Id＆＃34;和＆＃34; ChildId＆＃34;已被重命名为＆＃34; ParentId＆＃34;，以便模型有意义，以便数据类型有意义，然后如下：

  <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>CucumberJavaProject</groupId>
<artifactId>cucumberJava</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.11</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.seleniumhq.selenium</groupId>
        <artifactId>selenium-java</artifactId>
        <version>2.47.1</version>
    </dependency>
    <dependency>
        <groupId>info.cukes</groupId>
        <artifactId>cucumber-core</artifactId> 
        <version>1.2.4</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>info.cukes</groupId>
        <artifactId>cucumber-java</artifactId>
        <version>1.1.3</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>info.cukes</groupId>
        <artifactId>cucumber-junit</artifactId> 
        <version>1.2.4</version>
        <scope>test</scope>
    </dependency>


     <dependency>
        <groupId>info.cukes</groupId>
        <artifactId>cucumber-picocontainer</artifactId>
        <version>1.2.4</version>
    </dependency>
    <dependency>
        <groupId>info.cukes</groupId>
        <artifactId>gherkin</artifactId>
        <version>2.12.2</version>
    </dependency>


 </dependencies>  
 <build>
    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.1</version>
            <configuration>
                <source>1.6</source>
                <target>1.6</target>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.12</version>
            <configuration>
                <parallel>methods</parallel>
                <threadCount>20</threadCount>
                <redirectTestOutputToFile>true</redirectTestOutputToFile>
            </configuration>
        </plugin>
    </plugins>
</build>

产生以下输出：

CREATE TABLE TEST
(
    Id INTEGER, 
    ParentId INTEGER, 
    Name NVARCHAR(100), 
    TotalCount INTEGER 
);

INSERT INTO TEST( Id, ParentId, Name, TotalCount ) VALUES( 45627, 12568, 'Test1', 0 );
INSERT INTO TEST( Id, ParentId, Name, TotalCount ) VALUES( 52678, 45627, 'Test2', 0 );  
INSERT INTO TEST( Id, ParentId, Name, TotalCount ) VALUES( 23123, 45627, 'Test3', 7 );  
INSERT INTO TEST( Id, ParentId, Name, TotalCount ) VALUES( 54312, 45627, 'Test4', 3 );  
INSERT INTO TEST( Id, ParentId, Name, TotalCount ) VALUES( 32123, 45627, 'Test5', 0 );  
INSERT INTO TEST( Id, ParentId, Name, TotalCount ) VALUES( 12111, 45627, 'Test6', 1 );  
INSERT INTO TEST( Id, ParentId, Name, TotalCount ) VALUES( 32122, 45627, 'Test7', 0 );  
INSERT INTO TEST( Id, ParentId, Name, TotalCount ) VALUES( 43123, 45627, 'Test8', 0 );  

SELECT Parent.Id, SUM( Child.TotalCount ) AS Total
   FROM TEST AS Parent 
       LEFT JOIN TEST As Child ON Parent.id = Child.ParentId
GROUP BY Parent.Id;

根据上述假设，给定输入数据的正确输出是什么。

45627也会产生11，这是OP想要的。

如果问题被编辑有意义，我会相应地修改我的答案。

Sql子项的总和

2 个答案: