MS SQL 合并结果集并求和

业务情景：有这样一张表：其中Id列为表主键，Name为用户名，State为记录的状态值，Note为状态的说明，方便阅读。

需求描述：需要查询出这样的结果：某个人某种状态的记录数，如：张三，待审核记录数，审核中记录数，审核通过记录数；大概像这样：

解决方案：

1.建表和初始化测试数据： 

--1.建表语句
CREATE TABLE [dbo].[Content]
(
	[Id] [int] NULL,
	[Name]   [nvarchar](50) NULL,
	[State]  [int] NULL,
	[Note]   [nvarchar](50) NULL,
)  
GO
--2.初始化数据
INSERT INTO CONTENT VALUES(1,"张三",1,"待审核")
INSERT INTO CONTENT VALUES(2,"张三",2,"审核中")
INSERT INTO CONTENT VALUES(3,"张三",2,"审核中")
INSERT INTO CONTENT VALUES(4,"李四",1,"待审核")
INSERT INTO CONTENT VALUES(5,"李四",2,"审核中")
INSERT INTO CONTENT VALUES(5,"李四",3,"审核通过")</span>

2.查询语句：

SELECT NAME,
       SUM(审核通过) AS "审核通过",
       SUM(待审核) AS "待审核",
       SUM(审核中) AS "审核中"
FROM   (
           (
               SELECT NAME,
                      COUNT(*) AS "审核通过",
                      0 AS "审核中",
                      0 AS "待审核"
               FROM   CONTENT
               WHERE  [STATE] = 3
                      AND NAME IN ("张三", "李四")
               GROUP BY
                      NAME
           ) 
           
           UNION 
           
           (
               SELECT NAME,
                      0 AS "审核通过",
                      COUNT(*) AS "审核中",
                      0 AS "待审核"
               FROM   CONTENT
               WHERE  [STATE] = 2
                      AND NAME IN ("张三", "李四")
               GROUP BY
                      NAME
           ) 
           UNION 
           (
               SELECT NAME,
                      0 AS "审核通过",
                      0 AS "审核中",
                      COUNT(*) AS "待审核"
               FROM   CONTENT
               WHERE  [STATE] = 1
                      AND NAME IN ("张三", "李四")
               GROUP BY
                      NAME
           )
       )temp
GROUP BY
       NAME</span>

这里用到两个知识点：

1.UNION 操作符用于合并两个或多个 SELECT 语句的结果集。请注意，UNION 内部的 SELECT 语句必须拥有相同数量的列。列也必须拥有相似的数据类型。同时，每条 SELECT 语句中的列的顺序必须相同。

2.GROUP BY + 聚合函数(如SUM, COUNT, MAX, AVG等)统计数据。