SQL order-by
Microsoft Azure DocumentDB 支持通过 JSON 文档使用 SQL 查询文档。您可以在查询中使用 ORDER BY 子句根据数字和字符串对集合中的文档进行排序。该子句可以包含一个可选的 ASC/DESC 参数来指定必须检索结果的顺序。
我们将考虑与前面示例中相同的文档。
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
}
我们来看一个简单的例子。
以下是包含 ORDER BY 关键字的查询。
SELECT f.id, f.children[0].givenName,f.children[0].grade
FROM Families f
ORDER BY f.children[0].grade
执行上述查询时，会产生以下输出。
[
{
"id": "SmithFamily",
"givenName": "Michelle",
"grade": 1
},
{
"id": "AndersenFamily",
"grade": 5
},
{
"id": "WakefieldFamily",
"givenName": "Jesse",
"grade": 6
}
]
让我们考虑另一个简单的例子。
以下是包含 ORDER BY 关键字和 DESC 可选关键字的查询。
SELECT f.id, f.parents[0].familyName
FROM Families f
ORDER BY f.parents[0].familyName DESC
执行上述查询时，将产生以下输出。
[
{
"id": "WakefieldFamily",
"familyName": "Wakefield"
},
{
"id": "SmithFamily",
"familyName": "Smith"
},
{
"id": "AndersenFamily"
}
]
