Elasticsearch的学习笔记(二)

Elasticsearch的学习笔记(二)

默然
2022-04-26 / 0 评论 / 22 阅读 / 正在检测是否收录...

数据格式

Elasticsearch是面向文档型数据库,一条数据在这里就是一个文档。
为了方便大家理解,我们将 Elasticsearch 里存储文档数据和关系型数据库 MySQL 存储数据的概念进行一个类比

l2fy10b5.png

ES 里的 Index 可以看做一个库,而 Types 相当于表, Documents 则相当于表的行。这里 Types 的概念已经被逐渐弱化, Elasticsearch 6.X 中,一个 index 下已经只能包含一个type, Elasticsearch 7.X 中, Type 的概念已经被删除了。

创建索引

PUT http://localhost:9200/shopping
{
    "acknowledged": true,
    "shards_acknowledged": true,
    "index": "shopping"
}

查看当前索引

GET http://localhost:9200/shopping
{
    "shopping": {//索引名
        "aliases": {},//别名
        "mappings": {},//映射
        "settings": {//设置
            "index": {//设置 - 索引
                "creation_date": "1650959730840",//设置 - 索引 - 创建时间
                "number_of_shards": "1",//设置 - 索引 - 主分片数量
                "number_of_replicas": "1",//设置 - 索引 - 主分片数量
                "uuid": "Y2GAupofQFiHc5nsAlDe1w",//设置 - 索引 - 主分片数量
                "version": {//设置 - 索引 - 主分片数量
                    "created": "7080099"
                },
                "provided_name": "shopping"//设置 - 索引 - 主分片数量
            }
        }
    }
}

查看当前ES中所有的索引

GET http://localhost:9200/_cat/indices?v
health status index    uuid                   pri rep docs.count docs.deleted store.size pri.store.size
yellow open   shopping Y2GAupofQFiHc5nsAlDe1w   1   1          0            0       208b           208b
表头含义
health当前服务器健康状态: green(集群完整) yellow(单点正常、集群不完整) red(单点不正常)
status索引打开、关闭状态
index索引名
uuid索引统一编号
pri主分片数量
rep副本数量
docs.count可用文档数量
docs.deleted文档删除状态(逻辑删除)
store.size主分片和副分片整体占空间大小
pri.store.size主分片占空间大小

删除索引

DELETE http://localhost:9200/shopping
{
    "acknowledged": true
}

增加文档

POST http://localhost:9200/shopping/_doc

请求体JSON内容为:

{
    "title":"小米手机",
    "category":"小米",
    "images":"http://www.gulixueyuan.com/xm.jpg",
    "price":3999.00
}

注意,此处发送请求的方式必须为 POST,不能是 PUT,否则会发生错误 。

返回结果:

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "k63tZIAB6CX3m_v3vfQI",
    "_version": 1,
    "result": "created",
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 3,
    "_primary_term": 1
}

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://127.0.0.1:9200/shopping/_doc/1001,这样就可以指定 ID 为 1001 。

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1001",  //自定义唯一ID标识
    "_version": 3,
    "result": "updated",
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 4,
    "_primary_term": 1
}

此处需要注意:如果增加数据时明确数据主键,那么请求方式也可以为 PUT。

查询文档

通过主键ID查询文档:

GET http://localhost:9200/shopping/_doc/1001
{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1001",
    "_version": 3,
    "_seq_no": 4,
    "_primary_term": 1,
    "found": true,
    "_source": {
        "title": "小米手机",
        "category": "小米",
        "images": "http://www.gulixueyuan.com/xm.jpg",
        "price": 3999
    }
}

查询全部文档:

GET http://localhost:9200/shopping/_search
{
    "took": 2,    //查询花费时长(毫秒)
    "timed_out": false,  // 请求是否超时
    "_shards": {   //搜索了多少分片,成功、失败或者跳过了多个分片(明细)
        "total": 1,   //总分片数
        "successful": 1,   //成功分片数
        "skipped": 0,    //失败分片数
        "failed": 0  // 跳过分片数
    },
    "hits": {
        "total": {
            "value": 3,   // 找到的文档总数
            "relation": "eq"
        },
        "max_score": 1,  最相关的文档分数
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "kq3nZIAB6CX3m_v3APT6",
                "_score": 1,  //文档的相关性算分 (match_all 没有算分)
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "k63tZIAB6CX3m_v3vfQI",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "1001",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            }
        ]
    }
}

更新文档

全局更新

POST http://localhost:9200/shopping/_doc/1001

请求JSON数据:

{
    "title":"华为手机",
    "category":"华为",
    "images":"http://www.gulixueyuan.com/hw.jpg",
    "price":1999.00
}

返回结果:

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1001",
    "_version": 10,
    "result": "updated", //updated 表示数据被更新
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 13,
    "_primary_term": 1
}

局部更新

PUT http://localhost:9200/shopping/_update/1001
请求JSON数据:
{
    "doc": {
        "title":"小米手机",
        "category":"小米"
    }
}

返回结果:

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1001",
    "_version": 11,
    "result": "updated", //updated 表示数据被更新
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 14,
    "_primary_term": 1
}

删除文档

DELETE http://localhost:9200/shopping/_doc/1001

返回结果:

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1001",
    "_version": 12,
    "result": "deleted", // deleted 表示数据被删除
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 15,
    "_primary_term": 1
}

查询文档

查询全部

GET http://localhost:9200/shopping/_search

返回结果数据:

{
    "took": 1,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 4,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "kq3nZIAB6CX3m_v3APT6",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "k63tZIAB6CX3m_v3vfQI",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "l636ZIAB6CX3m_v3q_R5",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/hw.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ma37ZIAB6CX3m_v3BvQc",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/hw.jpg",
                    "price": 1999
                }
            }
        ]
    }
}

按条件查询(URL带参查询)

GET http://localhost:9200/shopping/_search?q=category:小米

返回结果:

{
    "took": 19,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 2,
            "relation": "eq"
        },
        "max_score": 1.8889232,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "kq3nZIAB6CX3m_v3APT6",
                "_score": 1.8889232,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "k63tZIAB6CX3m_v3vfQI",
                "_score": 1.8889232,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            }
        ]
    }
}

按条件查询(请求体带参查询)

POST http://localhost:9200/shopping/_search

请求体:

{
    "query": {
        "match": {
            "category": "小米"
        }
    }
}

返回结果:

{
    "took": 1,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 7,
            "relation": "eq"
        },
        "max_score": 0.99798226,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "kq3nZIAB6CX3m_v3APT6",
                "_score": 0.99798226,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "k63tZIAB6CX3m_v3vfQI",
                "_score": 0.99798226,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "n60KZYAB6CX3m_v3q_Tc",
                "_score": 0.99798226,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "oK0KZYAB6CX3m_v3rfQs",
                "_score": 0.99798226,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "oa0KZYAB6CX3m_v3rvS_",
                "_score": 0.99798226,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "oq0KZYAB6CX3m_v3sPQR",
                "_score": 0.99798226,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "o60KZYAB6CX3m_v3sfT8",
                "_score": 0.99798226,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            }
        ]
    }
}

查询全部数据(请求体带参查询)

POST http://localhost:9200/shopping/_search

请求体:

{
    "query": {
        "match_all": {}
    }
}

等同于下面此接口

GET http://127.0.0.1:9200/shopping/_search

返回结果:

{
    "took": 1,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 9,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "kq3nZIAB6CX3m_v3APT6",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "k63tZIAB6CX3m_v3vfQI",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "l636ZIAB6CX3m_v3q_R5",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/hw.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ma37ZIAB6CX3m_v3BvQc",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/hw.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "n60KZYAB6CX3m_v3q_Tc",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "oK0KZYAB6CX3m_v3rfQs",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "oa0KZYAB6CX3m_v3rvS_",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "oq0KZYAB6CX3m_v3sPQR",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "o60KZYAB6CX3m_v3sfT8",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            }
        ]
    }
}
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