sql语句中不需要的其他记录

Question

• mysql：Ver 14.14 Distrib 5.5.45，for Win64（x86）
• 操作系统：Windows Server 2008 R2

＆＃34;促进＆＃34;表格带

SELECT id, name FROM promotion ORDER BY id;

给出以下结果：

+----+--------------------------+
| id | name                     |
+----+--------------------------+
|  1 | Shared Web Hosting       |
|  4 | cPanel VPS               |
|  5 | Unmanaged VPS            |
|  6 | Windows VPS              |
|  7 | Dedicated Linux          |
|  8 | Dedicated Windows Server |
|  9 | Maintained Webhosting    |
| 10 | Domain Names             |
| 11 | Web Design               |
+----+--------------------------+

＆＃34;包＆＃34;表格带

SELECT a.id AS PackageID, a.planname AS PackageName, a.planid AS CategoryID 
FROM package a 
WHERE a.planid = 11 
ORDER BY a.planid, a.planname;

给出以下结果：

+-----------+--------------+------------+
| PackageID | PackageName  | CategoryID |
+-----------+--------------+------------+
|        40 | Innovative-1 |         11 |
|        46 | Innovative-2 |         11 |
|        47 | Innovative-3 |         11 |
|        38 | Intrinsic-1  |         11 |
|        42 | Intrinsic-2  |         11 |
|        43 | Intrinsic-3  |         11 |
|        39 | Median-1     |         11 |
|        44 | Median-2     |         11 |
|        45 | Median-3     |         11 |
|        41 | Quantum      |         11 |
+-----------+--------------+------------+

加入＆＃34;促销＆＃34;和＆＃34;包＆＃34;带

的表格

SELECT a.id AS PackageID, a.planname AS PackageName, a.planid
AS CategoryID, b.name 
AS CategoryName 
FROM package a 
LEFT OUTER JOIN promotion b 
ON a.planid = b.id 
ORDER BY a.planid, a.planname;

给出了以下结果：

+-----------+----------------+------------+--------------------------+
| PackageID | PackageName    | CategoryID | CategoryName             |
+-----------+----------------+------------+--------------------------+
|         1 | Web Hosting    |          1 | Shared Web Hosting       |
|         2 | VPS-1          |          4 | cPanel VPS               |
|         3 | VPS-2          |          4 | cPanel VPS               |
|         4 | VPS-3          |          4 | cPanel VPS               |
|         5 | VPS-4          |          4 | cPanel VPS               |
|         6 | VPS-5          |          4 | cPanel VPS               |
|         7 | VPS-6          |          4 | cPanel VPS               |
|         8 | uVPS-1         |          5 | Unmanaged VPS            |
|         9 | uVPS-2         |          5 | Unmanaged VPS            |
|        10 | uVPS-3         |          5 | Unmanaged VPS            |
|        11 | uVPS-4         |          5 | Unmanaged VPS            |
|        12 | uVPS-5         |          5 | Unmanaged VPS            |
|        13 | uVPS-6         |          5 | Unmanaged VPS            |
|        14 | wVPS-1         |          6 | Windows VPS              |
|        15 | wVPS-2         |          6 | Windows VPS              |
|        16 | wVPS-3         |          6 | Windows VPS              |
|        17 | wVPS-4         |          6 | Windows VPS              |
|        18 | wVPS-5         |          6 | Windows VPS              |
|        19 | wVPS-6         |          6 | Windows VPS              |
|        20 | Server 1       |          7 | Dedicated Linux          |
|        21 | Server 2       |          7 | Dedicated Linux          |
|        22 | Server 3       |          7 | Dedicated Linux          |
|        23 | Server 4       |          7 | Dedicated Linux          |
|        24 | wServer 1      |          8 | Dedicated Windows Server |
|        25 | wServer 2      |          8 | Dedicated Windows Server |
|        26 | wServer 3      |          8 | Dedicated Windows Server |
|        27 | wServer 4      |          8 | Dedicated Windows Server |
|        35 | Advanced-1     |          9 | Maintained Webhosting    |
|        36 | Advanced-2     |          9 | Maintained Webhosting    |
|        37 | Advanced-3     |          9 | Maintained Webhosting    |
|        29 | Basic-1        |          9 | Maintained Webhosting    |
|        30 | Basic-2        |          9 | Maintained Webhosting    |
|        31 | Basic-3        |          9 | Maintained Webhosting    |
|        32 | Intermediate-1 |          9 | Maintained Webhosting    |
|        33 | Intermediate-2 |          9 | Maintained Webhosting    |
|        34 | Intermediate-3 |          9 | Maintained Webhosting    |
|        55 | BIZ            |         10 | Domain Names             |
|        58 | BZ             |         10 | Domain Names             |
|        51 | CC             |         10 | Domain Names             |
|        28 | COM            |         10 | Domain Names             |
|        53 | INFO           |         10 | Domain Names             |
|        48 | NET            |         10 | Domain Names             |
|        56 | NU             |         10 | Domain Names             |
|        49 | ORG            |         10 | Domain Names             |
|        52 | TV             |         10 | Domain Names             |
|        50 | US             |         10 | Domain Names             |
|        57 | WS             |         10 | Domain Names             |
|        40 | Innovative-1   |         11 | Web Design               |
|        46 | Innovative-2   |         11 | Web Design               |
|        47 | Innovative-3   |         11 | Web Design               |
|        38 | Intrinsic-1    |         11 | Web Design               |
|        42 | Intrinsic-2    |         11 | Web Design               |
|        43 | Intrinsic-3    |         11 | Web Design               |
|        39 | Median-1       |         11 | Web Design               |
|        44 | Median-2       |         11 | Web Design               |
|        45 | Median-3       |         11 | Web Design               |
|        41 | Quantum        |         11 | Web Design               |
+-----------+----------------+------------+--------------------------+

现在当我执行此SQL命令时：

SELECT a.id 
AS PackageID, a.planname 
AS PackageName, a.planid 
AS CategoryID, b.name 
AS CategoryName 
FROM package a 
LEFT OUTER JOIN promotion b 
ON a.planid = b.id AND b.id = 11 
ORDER BY a.planid, a.planname;

给出了以下结果：

+-----------+----------------+------------+--------------+
| PackageID | PackageName    | CategoryID | CategoryName |
+-----------+----------------+------------+--------------+
|         1 | Web Hosting    |          1 | NULL         |
|         2 | VPS-1          |          4 | NULL         |
|         3 | VPS-2          |          4 | NULL         |
|         4 | VPS-3          |          4 | NULL         |
|         5 | VPS-4          |          4 | NULL         |
|         6 | VPS-5          |          4 | NULL         |
|         7 | VPS-6          |          4 | NULL         |
|         8 | uVPS-1         |          5 | NULL         |
|         9 | uVPS-2         |          5 | NULL         |
|        10 | uVPS-3         |          5 | NULL         |
|        11 | uVPS-4         |          5 | NULL         |
|        12 | uVPS-5         |          5 | NULL         |
|        13 | uVPS-6         |          5 | NULL         |
|        14 | wVPS-1         |          6 | NULL         |
|        15 | wVPS-2         |          6 | NULL         |
|        16 | wVPS-3         |          6 | NULL         |
|        17 | wVPS-4         |          6 | NULL         |
|        18 | wVPS-5         |          6 | NULL         |
|        19 | wVPS-6         |          6 | NULL         |
|        20 | Server 1       |          7 | NULL         |
|        21 | Server 2       |          7 | NULL         |
|        22 | Server 3       |          7 | NULL         |
|        23 | Server 4       |          7 | NULL         |
|        24 | wServer 1      |          8 | NULL         |
|        25 | wServer 2      |          8 | NULL         |
|        26 | wServer 3      |          8 | NULL         |
|        27 | wServer 4      |          8 | NULL         |
|        35 | Advanced-1     |          9 | NULL         |
|        36 | Advanced-2     |          9 | NULL         |
|        37 | Advanced-3     |          9 | NULL         |
|        29 | Basic-1        |          9 | NULL         |
|        30 | Basic-2        |          9 | NULL         |
|        31 | Basic-3        |          9 | NULL         |
|        32 | Intermediate-1 |          9 | NULL         |
|        33 | Intermediate-2 |          9 | NULL         |
|        34 | Intermediate-3 |          9 | NULL         |
|        55 | BIZ            |         10 | NULL         |
|        58 | BZ             |         10 | NULL         |
|        51 | CC             |         10 | NULL         |
|        28 | COM            |         10 | NULL         |
|        53 | INFO           |         10 | NULL         |
|        48 | NET            |         10 | NULL         |
|        56 | NU             |         10 | NULL         |
|        49 | ORG            |         10 | NULL         |
|        52 | TV             |         10 | NULL         |
|        50 | US             |         10 | NULL         |
|        57 | WS             |         10 | NULL         |
|        40 | Innovative-1   |         11 | Web Design   |
|        46 | Innovative-2   |         11 | Web Design   |
|        47 | Innovative-3   |         11 | Web Design   |
|        38 | Intrinsic-1    |         11 | Web Design   |
|        42 | Intrinsic-2    |         11 | Web Design   |
|        43 | Intrinsic-3    |         11 | Web Design   |
|        39 | Median-1       |         11 | Web Design   |
|        44 | Median-2       |         11 | Web Design   |
|        45 | Median-3       |         11 | Web Design   |
|        41 | Quantum        |         11 | Web Design   |
+-----------+----------------+------------+--------------+

现在给出上述信息，当我执行以下SQL语句时：

SELECT a.id 
AS PackageID, a.planname 
AS PackageName, a.planid 
AS CategoryID, b.name 
AS CategoryName 
FROM package a 
LEFT OUTER JOIN promotion b 
ON a.planid = b.id AND b.name = 'Web Design' 
ORDER BY a.planid, a.planname;

我得到以下结果：

+-----------+----------------+------------+--------------+
| PackageID | PackageName    | CategoryID | CategoryName |
+-----------+----------------+------------+--------------+
|         1 | Web Hosting    |          1 | NULL         |
|         2 | VPS-1          |          4 | NULL         |
|         3 | VPS-2          |          4 | NULL         |
|         4 | VPS-3          |          4 | NULL         |
|         5 | VPS-4          |          4 | NULL         |
|         6 | VPS-5          |          4 | NULL         |
|         7 | VPS-6          |          4 | NULL         |
|         8 | uVPS-1         |          5 | NULL         |
|         9 | uVPS-2         |          5 | NULL         |
|        10 | uVPS-3         |          5 | NULL         |
|        11 | uVPS-4         |          5 | NULL         |
|        12 | uVPS-5         |          5 | NULL         |
|        13 | uVPS-6         |          5 | NULL         |
|        14 | wVPS-1         |          6 | NULL         |
|        15 | wVPS-2         |          6 | NULL         |
|        16 | wVPS-3         |          6 | NULL         |
|        17 | wVPS-4         |          6 | NULL         |
|        18 | wVPS-5         |          6 | NULL         |
|        19 | wVPS-6         |          6 | NULL         |
|        20 | Server 1       |          7 | NULL         |
|        21 | Server 2       |          7 | NULL         |
|        22 | Server 3       |          7 | NULL         |
|        23 | Server 4       |          7 | NULL         |
|        24 | wServer 1      |          8 | NULL         |
|        25 | wServer 2      |          8 | NULL         |
|        26 | wServer 3      |          8 | NULL         |
|        27 | wServer 4      |          8 | NULL         |
|        35 | Advanced-1     |          9 | NULL         |
|        36 | Advanced-2     |          9 | NULL         |
|        37 | Advanced-3     |          9 | NULL         |
|        29 | Basic-1        |          9 | NULL         |
|        30 | Basic-2        |          9 | NULL         |
|        31 | Basic-3        |          9 | NULL         |
|        32 | Intermediate-1 |          9 | NULL         |
|        33 | Intermediate-2 |          9 | NULL         |
|        34 | Intermediate-3 |          9 | NULL         |
|        55 | BIZ            |         10 | NULL         |
|        58 | BZ             |         10 | NULL         |
|        51 | CC             |         10 | NULL         |
|        28 | COM            |         10 | NULL         |
|        53 | INFO           |         10 | NULL         |
|        48 | NET            |         10 | NULL         |
|        56 | NU             |         10 | NULL         |
|        49 | ORG            |         10 | NULL         |
|        52 | TV             |         10 | NULL         |
|        50 | US             |         10 | NULL         |
|        57 | WS             |         10 | NULL         |
|        40 | Innovative-1   |         11 | Web Design   |
|        46 | Innovative-2   |         11 | Web Design   |
|        47 | Innovative-3   |         11 | Web Design   |
|        38 | Intrinsic-1    |         11 | Web Design   |
|        42 | Intrinsic-2    |         11 | Web Design   |
|        43 | Intrinsic-3    |         11 | Web Design   |
|        39 | Median-1       |         11 | Web Design   |
|        44 | Median-2       |         11 | Web Design   |
|        45 | Median-3       |         11 | Web Design   |
|        41 | Quantum        |         11 | Web Design   |
+-----------+----------------+------------+--------------+

我需要的只是＆＃34;网页设计＆＃34;记录，我需要在SQL语句中更改哪些内容才能完成此任务？

Answer 1

我习惯于MSSQL和简单连接，忘记了外连接选择了所有记录。所以我将LEFT OUTER JOIN更改为INNER JOIN，它运行正常。