4 Elasticsearch之排序查询
4 Elasticsearch之排序查询
一 准备数据
PUT lqz/doc/1
{
"name":"顾老二",
"age":30,
"from": "gu",
"desc": "皮肤黑、武器长、性格直",
"tags": ["黑", "长", "直"]
}
PUT lqz/doc/2
{
"name":"大娘子",
"age":18,
"from":"sheng",
"desc":"肤白貌美，娇憨可爱",
"tags":["白", "富","美"]
}
PUT lqz/doc/3
{
"name":"龙套偏房",
"age":22,
"from":"gu",
"desc":"mmp，没怎么看，不知道怎么形容",
"tags":["造数据", "真","难"]
}
PUT lqz/doc/4
{
"name":"石头",
"age":29,
"from":"gu",
"desc":"粗中有细，狐假虎威",
"tags":["粗", "大","猛"]
}
PUT lqz/doc/5
{
"name":"魏行首",
"age":25,
"from":"广云台",
"desc":"仿佛兮若轻云之蔽月,飘飘兮若流风之回雪,mmp，最后竟然没有嫁给顾老二！",
"tags":["闭月","羞花"]
}
二 排序查询：sort
2.1 降序：desc
想到排序，出现在脑海中的无非就是升（正）序和降（倒）序。比如我们查询顾府都有哪些人，并根据age字段按照降序，并且，我只想看nmae和age字段：
GET lqz/doc/_search
{
"query": {
"match": {
"from": "gu"
}
},
"sort": [
{
"age": {
"order": "desc"
}
}
]
}
上例，在条件查询的基础上，我们又通过sort来做排序，根据age字段排序，是降序呢还是升序，由order字段控制，desc是降序。
结果如下：
{
"took" : 0,
"timed_out" : false,
"_shards" : {
"total" : 5,
"successful" : 5,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : 3,
"max_score" : null,
"hits" : [
{
"_index" : "lqz",
"_type" : "doc",
"_id" : "1",
"_score" : null,
"_source" : {
"name" : "顾老二",
"age" : 30,
"from" : "gu",
"desc" : "皮肤黑、武器长、性格直",
"tags" : [
"黑",
"长",
"直"
]
},
"sort" : [
30
]
},
{
"_index" : "lqz",
"_type" : "doc",
"_id" : "4",
"_score" : null,
"_source" : {
"name" : "石头",
"age" : 29,
"from" : "gu",
"desc" : "粗中有细，狐假虎威",
"tags" : [
"粗",
"大",
"猛"
]
},
"sort" : [
29
]
},
{
"_index" : "lqz",
"_type" : "doc",
"_id" : "3",
"_score" : null,
"_source" : {
"name" : "龙套偏房",
"age" : 22,
"from" : "gu",
"desc" : "mmp，没怎么看，不知道怎么形容",
"tags" : [
"造数据",
"真",
"难"
]
},
"sort" : [
22
]
}
]
}
}
上例中，结果是以降序排列方式返回的。
2.2 升序：asc
那么想要升序怎么搞呢？
GET lqz/doc/_search
{
"query": {
"match_all": {}
},
"sort": [
{
"age": {
"order": "asc"
}
}
]
}
上例，想要以升序的方式排列，只需要将order值换为asc就可以了。
结果如下：
{
"took" : 0,
"timed_out" : false,
"_shards" : {
"total" : 5,
"successful" : 5,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : 5,
"max_score" : null,
"hits" : [
{
"_index" : "lqz",
"_type" : "doc",
"_id" : "2",
"_score" : null,
"_source" : {
"name" : "大娘子",
"age" : 18,
"from" : "sheng",
"desc" : "肤白貌美，娇憨可爱",
"tags" : [
"白",
"富",
"美"
]
},
"sort" : [
18
]
},
{
"_index" : "lqz",
"_type" : "doc",
"_id" : "3",
"_score" : null,
"_source" : {
"name" : "龙套偏房",
"age" : 22,
"from" : "gu",
"desc" : "mmp，没怎么看，不知道怎么形容",
"tags" : [
"造数据",
"真",
"难"
]
},
"sort" : [
22
]
},
{
"_index" : "lqz",
"_type" : "doc",
"_id" : "5",
"_score" : null,
"_source" : {
"name" : "魏行首",
"age" : 25,
"from" : "广云台",
"desc" : "仿佛兮若轻云之蔽月,飘飘兮若流风之回雪,mmp，最后竟然没有嫁给顾老二！",
"tags" : [
"闭月",
"羞花"
]
},
"sort" : [
25
]
},
{
"_index" : "lqz",
"_type" : "doc",
"_id" : "4",
"_score" : null,
"_source" : {
"name" : "石头",
"age" : 29,
"from" : "gu",
"desc" : "粗中有细，狐假虎威",
"tags" : [
"粗",
"大",
"猛"
]
},
"sort" : [
29
]
},
{
"_index" : "lqz",
"_type" : "doc",
"_id" : "1",
"_score" : null,
"_source" : {
"name" : "顾老二",
"age" : 30,
"from" : "gu",
"desc" : "皮肤黑、武器长、性格直",
"tags" : [
"黑",
"长",
"直"
]
},
"sort" : [
30
]
}
]
}
}
上例，可以看到结果是以age从小到大的顺序返回结果。
三 不是什么数据类型都能排序
那么，你可能会问，除了age，能不能以别的属性作为排序条件啊？来试试：
GET lqz/chengyuan/_search
{
"query": {
"match_all": {}
},
"sort": [
{
"name": {
"order": "asc"
}
}
]
}
上例，我们以name属性来排序，来看结果：
{
"error": {
"root_cause": [
{
"type": "illegal_argument_exception",
"reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [name] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."
}
],
"type": "search_phase_execution_exception",
"reason": "all shards failed",
"phase": "query",
"grouped": true,
"failed_shards": [
{
"shard": 0,
"index": "lqz",
"node": "wrtr435jSgi7_naKq2Y_zQ",
"reason": {
"type": "illegal_argument_exception",
"reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [name] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."
}
}
],
"caused_by": {
"type": "illegal_argument_exception",
"reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [name] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.",
"caused_by": {
"type": "illegal_argument_exception",
"reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [name] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."
}
}
},
"status": 400
}
结果跟我们想象的不一样，报错了！
注意：在排序的过程中，只能使用可排序的属性进行排序。那么可以排序的属性有哪些呢？
- 数字
- 日期
其他的都不行！
