Added joining queries

Author: ba0708

Joining Queries/adding-documents.md

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+# Adding documents
+
+## Adding departments
+
+```
+PUT /department/_doc/1
+{
+  "name": "Development",
+  "join_field": "department"
+}
+```
+
+```
+PUT /department/_doc/2
+{
+  "name": "Marketing",
+  "join_field": "department"
+}
+```
+
+## Adding employees for departments
+
+```
+PUT /department/_doc/3?routing=1
+{
+  "name": "Bo Andersen",
+  "age": 28,
+  "gender": "M",
+  "join_field": {
+    "name": "employee",
+    "parent": 1
+  }
+}
+```
+
+```
+PUT /department/_doc/4?routing=2
+{
+  "name": "John Doe",
+  "age": 44,
+  "gender": "M",
+  "join_field": {
+    "name": "employee",
+    "parent": 2
+  }
+}
+```
+
+```
+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
+  }
+}
+```

Joining Queries/mapping-document-relationships.md

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+# Mapping document relationships
+
+```
+PUT /department
+{
+  "mappings": {
+    "_doc": {
+      "properties": {
+        "join_field": { 
+          "type": "join",
+          "relations": {
+            "department": "employee"
+          }
+        }
+      }
+    }
+  }
+}
+```

Joining Queries/multi-level-relations.md

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+# Multi-level relations
+
+## Creating the index with mapping
+
+```
+PUT /company
+{
+  "mappings": {
+    "_doc": {
+      "properties": {
+        "join_field": { 
+          "type": "join",
+          "relations": {
+            "company": ["department", "supplier"],
+            "department": "employee"
+          }
+        }
+      }
+    }
+  }
+}
+```
+
+## Adding a company
+
+```
+PUT /company/_doc/1
+{
+  "name": "My Company Inc.",
+  "join_field": "company"
+}
+```
+
+## Adding a department
+
+```
+PUT /company/_doc/2?routing=1
+{
+  "name": "Development",
+  "join_field": {
+    "name": "department",
+    "parent": 1
+  }
+}
+```
+
+## Adding an employee
+
+```
+PUT /company/_doc/3?routing=1
+{
+  "name": "Bo Andersen",
+  "join_field": {
+    "name": "employee",
+    "parent": 2
+  }
+}
+```
+
+## Adding some more test data
+```
+PUT /company/_doc/4
+{
+  "name": "Another Company, Inc.",
+  "join_field": "company"
+}
+```
+
+```
+PUT /company/_doc/5?routing=4
+{
+  "name": "Marketing",
+  "join_field": {
+    "name": "department",
+    "parent": 4
+  }
+}
+```
+
+```
+PUT /company/_doc/6?routing=4
+{
+  "name": "John Doe",
+  "join_field": {
+    "name": "employee",
+    "parent": 5
+  }
+}
+```
+
+## Example of querying multi-level relations
+
+```
+GET /company/_search
+{
+  "query": {
+    "has_child": {
+      "type": "department",
+      "query": {
+        "has_child": {
+          "type": "employee",
+          "query": {
+            "term": {
+              "name.keyword": "John Doe"
+            }
+          }
+        }
+      }
+    }
+  }
+}
+```

Joining Queries/nested-inner-hits.md

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+# Nested inner hits
+
+```
+GET /department/_search
+{
+  "_source": false,
+  "query": {
+    "nested": {
+      "path": "employees",
+      "inner_hits": {},
+      "query": {
+        "bool": {
+          "must": [
+            {
+              "match": {
+                "employees.position": "intern"
+              }
+            },
+            {
+              "term": {
+                "employees.gender.keyword": {
+                  "value": "F"
+                }
+              }
+            }
+          ]
+        }
+      }
+    }
+  }
+}
+```

Joining Queries/parent-child-inner-hits.md

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+# Parent/child inner hits
+
+## Including inner hits for the `has_child` query
+
+```
+GET /department/_search
+{
+  "query": {
+    "has_child": {
+      "type": "employee",
+      "inner_hits": {},
+      "query": {
+        "bool": {
+          "must": [
+            {
+              "range": {
+                "age": {
+                  "gte": 50
+                }
+              }
+            }
+          ],
+          "should": [
+            {
+              "term": {
+                "gender.keyword": "M"
+              }
+            }
+          ]
+        }
+      }
+    }
+  }
+}
+```
+
+## Including inner hits for the `has_parent` query
+
+```
+GET /department/_search
+{
+  "query": {
+    "has_parent": {
+      "inner_hits": {},
+      "parent_type": "department",
+      "query": {
+        "term": {
+          "name.keyword": "Development"
+        }
+      }
+    }
+  }
+}
+```

Joining Queries/querying-by-parent-id.md

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+# Querying by parent
+
+```
+GET /department/_search
+{
+  "query": {
+    "parent_id": {
+      "type": "employee",
+      "id": 1
+    }
+  }
+}
+```

Joining Queries/querying-child-documents-by-parent.md

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+# Querying child documents by parent
+
+## Matching child documents by parent criteria
+
+```
+GET /department/_search
+{
+  "query": {
+    "has_parent": {
+      "parent_type": "department",
+      "query": {
+        "term": {
+          "name.keyword": "Development"
+        }
+      }
+    }
+  }
+}
+```
+
+## Incorporating the parent documents' relevance scores
+
+```
+GET /department/_search
+{
+  "query": {
+    "has_parent": {
+      "parent_type": "department",
+      "score": true,
+      "query": {
+        "term": {
+          "name.keyword": "Development"
+        }
+      }
+    }
+  }
+}
+```