Elasticsearch - join queries, has_parent, has_child

es-4.json

// Mapping
PUT /department >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
{
  "mappings": {
    "properties": {
      "join_field": { 
        "type": "join",
        "relations": {
          "department": "employee"
        }
      }
    }
  }
}

{
  "acknowledged" : true,
  "shards_acknowledged" : true,
  "index" : "department"
}

// Adding departments
PUT /department/_doc/1 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
{
  "name": "Development",
  "join_field": "department"
}

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

// Above query is a shortened version of this.
PUT /department/_doc/2 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
{
  "name": "Marketing",
  "join_field": {
    "name": "department"
  }
}

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

// Adding employees
// The routing value is mandatory because parent and child documents 
// must be indexed on the same shard
PUT /department/_doc/3?routing=1 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
{
  "name": "Bo Andersen",
  "age": 28,
  "gender": "M",
  "join_field": {
    "name": "employee",
    "parent": 1
  }
}

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

PUT /department/_doc/4?routing=2
{
  "name": "John Doe",
  "age": 44,
  "gender": "M",
  "join_field": {
    "name": "employee",
    "parent": 2
  }
}

{
  "_index" : "department",
  "_type" : "_doc",
  "_id" : "4",
  "_version" : 1,
  "result" : "created",
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "failed" : 0
  },
  "_seq_no" : 3,
  "_primary_term" : 1
}

PUT /department/_doc/5?routing=1
{
  "name": "James Evans",
  "age": 32,
  "gender": "M",
  "join_field": {
    "name": "employee",
    "parent": 1
  }
}

PUT /department/_doc/6?routing=1
{
  "name": "Daniel Harris",
  "age": 52,
  "gender": "M",
  "join_field": {
    "name": "employee",
    "parent": 1
  }
}

PUT /department/_doc/7?routing=2
{
  "name": "Jane Park",
  "age": 23,
  "gender": "F",
  "join_field": {
    "name": "employee",
    "parent": 2
  }
}

PUT /department/_doc/8?routing=1
{
  "name": "Christina Parker",
  "age": 29,
  "gender": "F",
  "join_field": {
    "name": "employee",
    "parent": 1
  }
}

// Querying by parent
// Given this parent id, and the type to be searched.
GET /department/_search >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
{
  "query": {
    "parent_id": {
      "type": "employee",
      "id": 1
    }
  }
}

{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : 0.53899646,
    "hits" : [
      {
        "_index" : "department",
        "_type" : "_doc",
        "_id" : "3",
        "_score" : 0.53899646,
        "_routing" : "1",
        "_source" : {
          "name" : "Bo Andersen",
          "age" : 28,
          "gender" : "M",
          "join_field" : {
            "name" : "employee",
            "parent" : 1
          }
        }
      },
      {
        "_index" : "department",
        "_type" : "_doc",
        "_id" : "5",
        "_score" : 0.53899646,
        "_routing" : "1",
        "_source" : {
          "name" : "James Evans",
          "age" : 32,
          "gender" : "M",
          "join_field" : {
            "name" : "employee",
            "parent" : 1
          }
        }
      }
    ]
  }
}

// Has_parent query
// Text can be searched via full text search, like match etc.
// Keywords can be used with term queries and aaggregation.
// Defult mapping creates field (text) and field.keyword (keyword)
GET /department/_search >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
{
  "query": {
    "has_parent": {
      "parent_type": "department",
      "query": {
        "term": {
          "name.keyword": "Development"
        }
      }
    }
  }
}

{
  "took" : 6,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : 1.0,
    "hits" : [
      {
        "_index" : "department",
        "_type" : "_doc",
        "_id" : "3",
        "_score" : 1.0,
        "_routing" : "1",
        "_source" : {
          "name" : "Bo Andersen",
          "age" : 28,
          "gender" : "M",
          "join_field" : {
            "name" : "employee",
            "parent" : 1
          }
        }
      },
      {
        "_index" : "department",
        "_type" : "_doc",
        "_id" : "5",
        "_score" : 1.0,
        "_routing" : "1",
        "_source" : {
          "name" : "James Evans",
          "age" : 32,
          "gender" : "M",
          "join_field" : {
            "name" : "employee",
            "parent" : 1
          }
        }
      }
    ]
  }
}

// Attach relevant parent's score also, default is 1.0
GET /department/_search >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
{
  "query": {
    "has_parent": {
      "parent_type": "department",
      "score": true,
      "query": {
        "term": {
          "name.keyword": "Development"
        }
      }
    }
  }
}

{
  "took" : 4,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : 1.3862942,
    "hits" : [
      {
        "_index" : "department",
        "_type" : "_doc",
        "_id" : "3",
        "_score" : 1.3862942,
        "_routing" : "1",
        "_source" : {
          "name" : "Bo Andersen",
          "age" : 28,
          "gender" : "M",
          "join_field" : {
            "name" : "employee",
            "parent" : 1
          }
        }
      },
      {
        "_index" : "department",
        "_type" : "_doc",
        "_id" : "5",
        "_score" : 1.3862942,
        "_routing" : "1",
        "_source" : {
          "name" : "James Evans",
          "age" : 32,
          "gender" : "M",
          "join_field" : {
            "name" : "employee",
            "parent" : 1
          }
        }
      }
    ]
  }
}

// has_child query
GET /department/_search >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
{
  "query": {
    "has_child": {
      "type": "employee",
      "query": {
        "bool": {
          "must": [
            {
              "range": {
                "age": {
                  "lte": 50
                }
              }
            }
          ],
          "should": [
            {
              "term": {
                "gender.keyword": "M"
              }
            }
          ]
        }
      }
    }
  }
}

{
  "took" : 3,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : 1.0,
    "hits" : [
      {
        "_index" : "department",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 1.0,
        "_source" : {
          "name" : "Development",
          "join_field" : "department"
        }
      },
      {
        "_index" : "department",
        "_type" : "_doc",
        "_id" : "2",
        "_score" : 1.0,
        "_source" : {
          "name" : "Marketing",
          "join_field" : "department"
        }
      }
    ]
  }
}

// Relevance score with score_mode
GET /department/_search >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
{
  "query": {
    "has_child": {
      "type": "employee",
      "score_mode": "sum", 
      "query": {
        "bool": {
          "must": [
            {
              "range": {
                "age": {
                  "gte": 10
                }
              }
            }
          ],
          "should": [
            {
              "term": {
                "gender.keyword": {
                  "value": "M"
                }
              }
            }
          ]
        }
      }
    }
  }
}

{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : 2.2670627,
    "hits" : [
      {
        "_index" : "department",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 2.2670627,
        "_source" : {
          "name" : "Development",
          "join_field" : "department"
        }
      },
      {
        "_index" : "department",
        "_type" : "_doc",
        "_id" : "2",
        "_score" : 1.1335313,
        "_source" : {
          "name" : "Marketing",
          "join_field" : "department"
        }
      }
    ]
  }
}

// Specifying min and max children
GET /department/_search >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
{
  "query": {
    "has_child": {
      "type": "employee",
      "score_mode": "sum",
      "min_children": 2,
      "max_children": 5, 
      "query": {
        "bool": {
          "must": [
            {
              "range": {
                "age": {
                  "gte": 10
                }
              }
            }
          ],
          "should": [
            {
              "term": {
                "gender.keyword": {
                  "value": "M"
                }
              }
            }
          ]
        }
      }
    }
  } 
}

{
  "took" : 2,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 2.2670627,
    "hits" : [
      {
        "_index" : "department",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 2.2670627,
        "_source" : {
          "name" : "Development",
          "join_field" : "department"
        }
      }
    ]
  }
}