Elasticsearch-核心篇(5)-文档操作
文章目录
- 一、添加文档
- 二、更新文档
- 2.1 全量更新
- 2.2 增量更新
- 三、查询文档
- 3.1 单个查询
- 3.2 查询所有
- 四、删除文档
- 4.1 删除单个文档
- 4.2 条件删除文档
一、添加文档
操作说明
- 文档可以类比为关系型数据库中的表数据，添加的数据格式为 JSON 格式
- 注意需要在索引后面添加_doc，表示操作文档
- 在未指定id生成情况，每执行一次post将生成一个新文档
- 如果index不存在，将会默认创建
命令示例
POST es/_doc{"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999}
返回示例
{"_index"【索引】: "es","_type"【类型-文档】: "_doc","_id"【唯一标识】: "DBeE23kBo6bwxxzx9qzl", #可以类比为MySQL中的主键，随机生成"_version"【版本】: 1,"result"【结果】: "created", #这里的create表示创建成功"_shards"【分片】: {"total"【分片 - 总数】: 2,"successful"【分片 - 成功】: 1,"failed"【分片 - 失败】: 0},"_seq_no": 0,"_primary_term": 1}
错误说明
不允许使用PUT提交，将会报错
{
"error": "Incorrect HTTP method for uri [/es/_doc] and method [GET], allowed: [POST]","status": 405
}
不能遗忘_doc，将会报错
{
"error": "Incorrect HTTP method for uri [/es] and method [POST], allowed: [GET, DELETE, PUT, HEAD]","status": 405
}
高级操作
指定生成id
- 上面的数据创建后，由于没有指定数据唯一性标识（ID），默认情况下，ES服务器会随机生成一个
如果想要自定义唯一性标识，需要在创建时指定：http://{ {ip:port}}/es/_doc/1
- http://\{ {ip:port}}//_doc/
- 指定后将会创建成功，重复执行请求时将更新文档，而不是创建新文档，此时version字段将更新
{
"_index": "es","_type": "_doc","_id"【此处id变成指定的id】: "1","_version"【版本每次都会更新】: 4,"result": "updated","_shards": {"total": 2,"successful": 1,"failed": 0},"_seq_no": 7,"_primary_term": 1
}
PUT创建文档，在未指定id时put创建文档将会报错，而指定id后可以通过put创建或者更新文档，只是请求方式变，其他内容不变
二、更新文档
2.1 全量更新
操作说明
- 和新增文档一样，输入相同的 URL 地址请求，如果请求体变化，会将原有的数据内容覆盖
命令示例
POST es/_doc/1{"title": "华为手机","category": "华为","images": "http://www.gulixueyuan.com/hw.jpg","price": 4999.0}
返回示例
{"_index": "es","_type": "_doc","_id": "1","_version"【每修改一次版本号+1】: 7,"result"【updated表示更新】: "updated","_shards"【分片信息】: {"total": 2,"successful": 1,"failed": 0},"_seq_no": 10,"_primary_term": 1}
错误说明
更新不要忘记_doc，否则将会报错
- http://{ {ip:port}}/es/1
{
"error": {"root_cause": [{"type": "illegal_argument_exception","reason": "Rejecting mapping update to [es] as the final mapping would have more than 1 type: [_doc, 1]"}],"type": "illegal_argument_exception","reason": "Rejecting mapping update to [es] as the final mapping would have more than 1 type: [_doc, 1]"},"status": 400
}
2.2 增量更新
操作说明
- 通过指定_doc方式默认是全量更新，如果需要更新指定字段则需要将**_doc改为_update**
- 请求内容需要增加doc表示，原始{“key”: value}，更新{“doc”: {“key”: value}}
命令示例
POST es/_update/1{"doc": {"price": 1999}}
返回示例
{"_index": "es","_type": "_doc","_id": "1","_version": 8,"result": "updated","_shards": {"total": 2,"successful": 1,"failed": 0},"_seq_no": 11,"_primary_term": 1}
查询结果，看到price已经更新
{
"_index": "es","_type": "_doc","_id": "1","_version": 8,"_seq_no": 11,"_primary_term": 1,"found": true,"_source": {"title": "华为手机","category": "华为","images": "http://www.gulixueyuan.com/hw.jpg","price": 1999}
}
错误说明
不能忘记请求参数中的doc
- 请求参数
{
"price": 1999
}
- 错误信息
{
"error": {"root_cause": [{"type": "x_content_parse_exception","reason": "[2:3] [UpdateRequest] unknown field [price]"}],"type": "x_content_parse_exception","reason": "[2:3] [UpdateRequest] unknown field [price]"},"status": 400
}
三、查询文档
3.1 单个查询
操作说明
- 查看文档时，需要指明文档的唯一性标识，类似于 MySQL 中数据的主键查询
命令示例
GET es/_doc/1
返回示例
{"_index"【索引名称】: "es","_type"【索引类型】: "_doc","_id"【id信息】: "1","_version"【当前版本】: 4,"_seq_no": 7,"_primary_term": 1,"found"【查询结果，true表示查找到，false表示未查找到】: true,"_source"【表示原始数据信息】: {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999}}
错误说明
文档不存在时found为false
{
"_index": "es","_type": "_doc","_id": "12","found"【未找到】: false
}
3.2 查询所有
操作说明
- 上述只能查询单个，可以查询所有文档
- 将**_doc/替换为_search**
命令示例
GET es/_search
返回示例
{"took": 1,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits"【命中统计】: {"total"【命中总数】: {"value": 1,"relation": "eq"},"max_score": 1,"hits"【命中信息】: [{"_index": "es","_type": "_doc","_id": "GBe923kBo6bwxxzxoKxP","_score": 1,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999}}]}}
四、删除文档
4.1 删除单个文档
操作说明
- 删除一个文档不会立即从磁盘上移除，它只是被标记成已删除（逻辑删除）
命令示例
DELETE es/_doc/1
返回示例
{"_index": "es","_type": "_doc","_id": "1","_version"【删除也会更新版本】: 9,"result"【删除结果】: "deleted","_shards"【分片删除】: {"total": 2,"successful": 1,"failed": 0},"_seq_no": 12,"_primary_term": 1}
错误说明
删除不存在的文档
{
"_index": "es","_type": "_doc","_id": "1","_version": 1,"result"【文档未找到】: "not_found","_shards": {"total": 2,"successful": 1,"failed": 0},"_seq_no": 13,"_primary_term": 1
}
4.2 条件删除文档
操作说明
- 一般删除数据都是根据文档的唯一性标识进行删除，实际操作时，也可以根据条件对多条数据进行删除
不指定ID分别增加多条数据，使用创建文档时的脚本
{
"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999
}
条件查询需要http://{ {ip:port}}/es/_delete_by_query
- 替换_doc及后的内容为**_delete_by_query**根据query删除
- 查询请求参数需要使用query字段表示，然后在其中再使用match表示删除匹配的信息
- 注意：条件删除需要使用POST
命令示例
POST es/_delete_by_query{"query": {"match": {"price": 3999}}}
返回示例
{"took": 28,"timed_out"【是否超时】: false,"total"【总数量】: 4,"deleted"【删除数量】: 4,"batches"【批次】: 1,"version_conflicts": 0,"noops": 0,"retries": {"bulk": 0,"search": 0},"throttled_millis": 0,"requests_per_second": -1,"throttled_until_millis": 0,"failures": []}
错误说明
删除是使用post，不是delete，否则将会报错
{
"error": "Incorrect HTTP method for uri [/es/_delete_by_query] and method [DELETE], allowed: [POST]","status": 405
}
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