乐易云

新增：

POST /test_index/_doc
{
  "doc": {
    "name":"aaa",
    "price": 100009.00,
    "desc":"very good"
  }
}

修改：

POST /{indexName}/_update/{id}
{
  "doc": {
    "fieldName" : "fieldValue"
  }
}

举例：

POST /test_index/_update/AVYrxH8BeM2aFHTN9y9g
{
  "doc": {
    "name" : "test_index1_shanghai"
  }
}

这种格式已经不再适用，会报错：

POST /{indexName}/_doc/{id}/_update
或者
POST /indexName/{id}/_update

返回错误信息
{
  "error" : "no handler found for uri [/test_index/_doc/AVYrxH8BeM2aFHTN9y9g/_update?pretty=true] and method [POST]"
}

  同样，下面的命令会导致全量更新，如果操作不当，可能会丢失旧版本的数据

POST /test_index/_doc/ClaHxn8BeM2aFHTN-i_e
{
  "doc": {
    "name":"tea cake",
    "price" :39.00,
    "production date":"2022-03-26"
  }
}

并发修改：

以往ES的并发修改使用的是乐观锁机制，使用的时候需要指定version，但是目前version已经不再适用。以下是指定version时ES给出的提示信息：

{
  "error" : {
    "root_cause" : [
      {
        "type" : "action_request_validation_exception",
        "reason" : "Validation Failed: 1: internal versioning can not be used for optimistic concurrency control. Please use `if_seq_no` and `if_primary_term` instead;"
      }
    ],
    "type" : "action_request_validation_exception",
    "reason" : "Validation Failed: 1: internal versioning can not be used for optimistic concurrency control. Please use `if_seq_no` and `if_primary_term` instead;"
  },
  "status" : 400
}

现在，在并发修改的场景下，需要使用另外两个属性。

if_seq_no和if_primary_term。这两个属性在新增和根据id查询成功后，ES会返回当前数据的seq_no和_primary_term。

如果把这两个属性放在请求体中，会提示使用方式不对

{
  "error" : {
    "root_cause" : [
      {
        "type" : "mapper_parsing_exception",
        "reason" : "Field [_seq_no] is a metadata field and cannot be added inside a document. Use the index API request parameters."
      }
    ],
    "type" : "mapper_parsing_exception",
    "reason" : "failed to parse field [_seq_no] of type [_seq_no] in document with id 'ClaHxn8BeM2aFHTN-i_e'. Preview of field's value: '20'",
    "caused_by" : {
      "type" : "mapper_parsing_exception",
      "reason" : "Field [_seq_no] is a metadata field and cannot be added inside a document. Use the index API request parameters."
    }
  },
  "status" : 400
}

正确的方式：

POST /{indexName}/_doc/{id}?if_seq_no={预期的seq_no}&if_primary_term={预期的primary_term}
{
  "doc": {
    "name":"tea cake",
    "price" :138.00
  }
}

 例子：

POST /test_index/_doc/ClaHxn8BeM2aFHTN-i_e?if_seq_no=20&if_primary_term=1
{
  "doc": {
    "name":"tea cake",
    "price" :138.00
  }
}

查询：

条件查询：

GET /test_index/_search
{
  "query": {
    "match" : {
    "_id" : "AVYrxH8BeM2aFHTN9y9g"
  }
  }
}

查询索引下所有的数据，和以前版本保持一致

GET /{indexName}/_search
{
  "query": {
    "match_all": {}
  }
}

举例：

GET /test_index/_search
{
  "query": {
    "match_all": {}
  }
}

根据_id查询

GET /test_index/_doc/B1ZaxX8BeM2aFHTNly-A

批量查询

如果根据多个id查询多条数据，需要用到_mget。目前_mget必须要指定index，否则会报错：

{
  "error" : {
    "root_cause" : [
      {
        "type" : "action_request_validation_exception",
        "reason" : "Validation Failed: 1: index is missing for doc 0;2: index is missing for doc 1;"
      }
    ],
    "type" : "action_request_validation_exception",
    "reason" : "Validation Failed: 1: index is missing for doc 0;2: index is missing for doc 1;"
  },
  "status" : 400
}

正确的方式

GET /{indexName}/_mget
{
  "docs":[
    {
      "_id":"xxx"
    },
    {
      "_id":"xxx"
    }
    ]
}

举例：

GET /test_index/_mget
{
  "docs":[
    {
      "_id":"A1YsxH8BeM2aFHTNES_u"
    },
    {
      "_id":"BFYsxH8BeM2aFHTNFy-m"
    }
    ]
}

那不指定索引，可不可以查询所有数据呢？

GET _search
{
  "query": {
    "match_all": {}
  }
}

草稿，内容正在逐渐完善。。