BETWEEN关键字用于表示对SQL范围内的值范围的查询. BETWEEN可用于字符串或数字.在DocumentDB和ANSI SQL中使用BETWEEN的主要区别在于,您可以针对混合类型的属性表达范围查询.
例如,在某些文档中,您可能有"等级" "作为一个数字,在其他文件中,它可能是字符串.在这些情况下,两种不同类型的结果之间的比较是"未定义的",并且将跳过该文档.
让我们考虑前一个示例中的三个文档.以下是 AndersenFamily 文件.
{ "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 文件.
{ "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 文件.
{ "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 }
让我们看一个例子,其中查询返回所有家庭文件,其中第一个孩子的成绩在1-5之间(包括两者).
以下是使用BETWEEN关键字然后使用AND逻辑运算符的查询.
SELECT * FROM Families.children[0] c WHERE c.grade BETWEEN 1 AND 5
执行上述查询时,会产生以下输出.
[ { "givenName": "Michelle", "gender": "female", "grade": 1 }, { "firstName": "Henriette Thaulow", "gender": "female", "grade": 5, "pets": [ { "givenName": "Fluffy", "type": "Rabbit" } ] } ]
要显示上一个示例范围之外的成绩,请使用NOT BETWEEN,如以下查询中所示.
SELECT * FROM Families.children[0] c WHERE c.grade NOT BETWEEN 1 AND 5
执行此查询时.它产生以下输出.
[ { "familyName": "Merriam", "givenName": "Jesse", "gender": "female", "grade": 6, "pets": [ { "givenName": "Charlie Brown", "type": "Dog" }, { "givenName": "Tiger", "type": "Cat" }, { "givenName": "Princess", "type": "Cat" } ] }]