DocumentDB SQL——关键字 Between

关键字 BETWEEN 用于表示对值范围的查询，就像在 SQL 中一样。BETWEEN 可用于字符串或数字。在 DocumentDB 与 ANSI SQL 中使用 BETWEEN 的主要区别在于，您可针对混合类型的属性表示范围查询。

例如，在某些文档中，可能将“grade”设为数字，而其他文档中，可能将其设为字符串。在这些情况下，“未定义”两个不同类型的结果之间的比较，并且文档将被跳过。

让我们考虑前一个示例中的三个文档。以下是 **AndersenFamily** 文档。

{ 
   "id": "AndersenFamily", 
   "lastName": "Andersen", 
	
   "parents": [ 
      { "firstName": "Thomas", "relationship":  "father" }, 
      { "firstName": "Mary Kay", "relationship":  "mother" } 
   ],
	
   "children": [ 
      { 
         "firstName": "Henriette Thaulow", 
         "gender": "female", 
         "grade": 5, 
         "pets": [ { "givenName": "Fluffy", "type":  "Rabbit" } ] 
      } 
   ],
	
   "location": { "state": "WA", "county": "King", "city": "Seattle" }, 
   "isRegistered": true 
} 

以下是 **SmithFamily** 文档。

{ 
   "id": "SmithFamily", 
	
   "parents": [ 
      { "familyName": "Smith", "givenName": "James" }, 
      { "familyName": "Curtis", "givenName": "Helen" }
   ],
	
   "children": [ 
      { 
         "givenName": "Michelle", 
         "gender": "female", 
         "grade": 1 
      }, 
		
      { 
         "givenName": "John", 
         "gender": "male", 
         "grade": 7,
			
         "pets": [ 
            { "givenName": "Tweetie", "type": "Bird" } 
         ] 
      } 
   ],
	
   "location": { 
      "state": "NY", 
      "county": "Queens", 
      "city": "Forest Hills" 
   }, 
	
   "isRegistered": true 
} 

以下是 **WakefieldFamily** 文档。

{ 
   "id": "WakefieldFamily", 
	
   "parents": [ 
      { "familyName": "Wakefield", "givenName": "Robin" }, 
      { "familyName": "Miller", "givenName": "Ben" } 
   ],
	
   "children": [ 
      { 
         "familyName": "Merriam", 
         "givenName": "Jesse", 
         "gender": "female", 
         "grade": 6,
			
         "pets": [ 
            { "givenName": "Charlie Brown", "type": "Dog" }, 
            { "givenName": "Tiger", "type": "Cat" }, 
            { "givenName": "Princess", "type": "Cat" } 
         ] 
      },
		
      { 
         "familyName": "Miller", 
         "givenName": "Lisa", 
         "gender": "female", 
         "grade": 3, 
			
         "pets": [ 
            { "givenName": "Jake", "type": "Snake" } 
         ] 
      } 
   ],
	
   "location": { "state": "NY", "county": "Manhattan", "city": "NY" }, 
   "isRegistered": false 
} 

让我们看一个示例，其中查询返回所有第一个孩子成绩在 1-5 之间（包括 1 和 5）的家庭文档。

以下是使用关键字 BETWEEN 然后使用逻辑运算符 AND 的查询。

SELECT * 
FROM Families.children[0] c 
WHERE c.grade BETWEEN 1 AND 5

执行上述查询时，会生成以下输出。

[ 
   { 
      "givenName": "Michelle", 
      "gender": "female", 
      "grade": 1 
   }, 
	
   { 
      "firstName": "Henriette Thaulow", 
      "gender": "female", 
      "grade": 5, 
		
      "pets": [ 
         { 
            "givenName": "Fluffy",
            "type": "Rabbit" 
         } 
      ] 
   } 
]

要显示超出前一个示例范围的成绩，请如以下查询中所示使用 NOT BETWEEN。

SELECT * 
FROM Families.children[0] c 
WHERE c.grade NOT BETWEEN 1 AND 5

执行此查询时，会产生以下输出。

[ 
   { 
      "familyName": "Merriam", 
      "givenName": "Jesse", 
      "gender": "female", 
      "grade": 6, 
		
      "pets": [ 
         { 
            "givenName": "Charlie Brown", 
            "type": "Dog" 
         }, 
			
         { 
            "givenName": "Tiger", 
            "type": "Cat" 
         },
			
         {
            "givenName": "Princess", 
            "type": "Cat" 
         } 
      ] 
   }
]