主要知识点
1、field分类
2、object field类型的存储
一、field类型分类
1、multivalue field
{ "tags": [ "tag1", "tag2" ]}
建立索引时与string是一样的，数据类型不能混
2、empty field
null，[]，[null]
3、object field
向es插入以下数据
PUT /company/employee/1
{
"address": {
"country": "china",
"province": "guangdong",
"city": "guangzhou"
},
"name": "jack",
"age": 27,
"join_date": "2017-01-01"
}
其中address就是object类型，也就是address里面是一个json格式的数据。
再执行GET /company/_mapping/employee，结果是：
{
"company": {
"mappings": {
"employee": {
"properties": {
"address": {
"properties": {
"city": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"country": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"province": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
}
}
},
"age": {
"type": "long"
},
"join_date": {
"type": "date"
},
"name": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
}
}
}
}
}
}
二、object field类型的存储
用head进行查看，es是按以下方式进行存储：
{
"name": "jack",
"age": 27,
"join_date":"2017-01-01",
"address.country":"china",
"address.province": "guangdong",
"address.city":"guangzhou"
}
如果是更复杂的数据，如下面这条
{
"authors": [
{ "age": 26, "name": "Jack White"},
{ "age": 55, "name": "Tom Jones"},
{ "age": 39, "name": "Kitty Smith"}
]
}
在es内部存储方式如下：
{
"authors.age": [26, 55, 39],
"authors.name": [jack, white, tom, jones, kitty, smith]
}