Question

我遇到了SQL查询（对于SQL Server）。我是SQL新手，我没有取得多大进展。我已经创建了一个测试标记的测试项目。

我有3张表如下：

Monster: 
Name     Description              EatsPeople
Vampire  Pale, afraid of light    True
Ghost    See-through, annoying    False
Wraith   Green-ish, ugly, dumb    True

TagLookup:
Name    ID
Ghost   1
Ghost   2
Wraith  1

Tags:
ID    Text                      Value
1     Green                     green-skin
2     Screams like a banshee    banshee-call

我正在尝试选择标记值为'green-skin'的所有怪物。

Answer 1

假设Monsters.Name中的Tags.Value，Name-ID和TagLookup组合都是唯一的：

SELECT m.Name, m.Description, m.EatsPeople
  FROM dbo.Monster AS m
  INNER JOIN dbo.TagLookup AS tl
    ON m.Name = tl.Name
  INNER JOIN dbo.Tags AS t
    ON t.ID = tl.ID
    AND t.Value = 'green-skin';

SQL Server查询：标记查询

1 个答案: