Elasticsearch-核心篇(6)-映射操作

川长思鸟来 2022-09-06 15:19 120阅读 0赞

### 文章目录 ###

*  一、创建映射
 *   *  1.1 创建时映射
     *  1.2 映射修改
     *  1.3 添加时映射
 *  二、查看映射

# 一、创建映射 #

1.  有了索引库，等于有了数据库中的database
2.  接下来就需要建索引库(index)中的映射，类似于数据库(database)中的表结构(table)
3.  创建数据库表需要设置字段名称，类型，长度，约束等；索引库也一样，需要知道这个类型下有哪些字段，每个字段有哪些约束信息，这就叫做映射(mapping)
4.  如果不指定映射将会默认按照给定的类型自动添加对应映射

## 1.1 创建时映射 ##

1.  可以在创建索引时指定映射
    
     *  其中mappings.properties为固定结构，指定创建映射属性

PUT index
    { 
      "mappings" : { 
          "properties" : { 
            "id" : { 
              "type" : "long"
            },
            "title" : { 
              "type" : "text"
            }
          }
      }
    }

1.  创建完成后将会返回创建信息

{ 
      "index" : { 
        "aliases" : {  },
        "mappings" : { 
          "properties" : { 
            "id" : { 
              "type" : "long"
            },
            "title" : { 
              "type" : "text"
            }
          }
        },
        "settings" : { 
          "index" : { 
            "creation_date" : "1623072136760",
            "number_of_shards" : "1",
            "number_of_replicas" : "1",
            "uuid" : "aatM8ty0QQuZWXo-99lvnA",
            "version" : { 
              "created" : "7080099"
            },
            "provided_name" : "index"
          }
        }
      }
    }

## 1.2 映射修改 ##

1.  可以对已经存在的索引添加映射
2.  需要使用 PUT /\_mapping
3.  修改时只需要指定properties即可，不需要指定mappings

PUT index/_mapping
    { 
      "properties" : { 
        "id" : { 
          "type" : "long"
        },
        "title" : { 
          "type" : "text"
        }
      }
    }

1.  修改结果

{ 
      "acknowledged" : true
    }

## 1.3 添加时映射 ##

1.  如果不明确指定，则将会在添加数据时自动判定
2.  创建普通索引，此时没有映射信息

{ 
      "index" : { 
        "aliases" : {  },
        "mappings" : {  },
        "settings" : { 
          "index" : { 
            "creation_date" : "1623072418993",
            "number_of_shards" : "1",
            "number_of_replicas" : "1",
            "uuid" : "682iz4t_TRa-1Nc7bfm-ng",
            "version" : { 
              "created" : "7080099"
            },
            "provided_name" : "index"
          }
        }
      }
    }

1.  向索引中添加数据

POST index/_doc/1
    { 
      "id": 3,
    	"title": "华为手机",
    	"category": "华为"
    }

1.  将会自动识别对应值的映射

{ 
      "index" : { 
        "aliases" : {  },
        "mappings" : { 
          "properties" : { 
            "category" : { 
              "type" : "text",
              "fields" : { 
                "keyword" : { 
                  "type" : "keyword",
                  "ignore_above" : 256
                }
              }
            },
            "id" : { 
              "type" : "long"
            },
            "title" : { 
              "type" : "text",
              "fields" : { 
                "keyword" : { 
                  "type" : "keyword",
                  "ignore_above" : 256
                }
              }
            }
          }
        },
        "settings" : { 
          "index" : { 
            "creation_date" : "1623072418993",
            "number_of_shards" : "1",
            "number_of_replicas" : "1",
            "uuid" : "682iz4t_TRa-1Nc7bfm-ng",
            "version" : { 
              "created" : "7080099"
            },
            "provided_name" : "index"
          }
        }
      }
    }

# 二、查看映射 #

1.  查看索引完全信息，内容包含映射信息

GET index

1.  指定查询索引信息

GET index/_mapping

{ 
      "index" : { 
        "mappings" : { 
          "properties" : { 
            "category" : { 
              "type" : "text",
              "fields" : { 
                "keyword" : { 
                  "type" : "keyword",
                  "ignore_above" : 256
                }
              }
            },
            "id" : { 
              "type" : "long"
            },
            "title" : { 
              "type" : "text",
              "fields" : { 
                "keyword" : { 
                  "type" : "keyword",
                  "ignore_above" : 256
                }
              }
            }
          }
        }
      }
    }