title: Making an elasticsearch nested query for match on all fields of nested object
body: <p>The basic question is as follows:
  Is there a convenient way to specify a multi-field match on all fields for a nested query?
  For a normal query <code>{ match : { _all : "query string" }}</code> works.
  This doesn't work in a nested query for perhaps because the nested object doesn't have an _all? </p>
  
  <p>The more detailed question below:</p>
  
  <p>I have a nested document called "Parent" as follows:</p>
  
  <pre><code>{
      "children" : [
          { 
              "field_a": "value_a_1",
              "field_b" : "value_b_1",
              "field_c" : [ {
                  "field_c_a" : "value_c_a_1",
                  "field_c_b" : "value_c_b_1"
              } ]
          },
          { 
              "field_a": "value_a_2",
              "field_b" : "value_b_2",
              "field_c" : [ {
                  "field_c_a" : "value_c_a_2",
                  "field_c_b" : "value_c_b_2"
              } ]
          }
      ]
  }
  </code></pre>
  
  <p>This is the mapping I used for making the children nested objects:</p>
  
  <pre><code>"Parent" : {
      "properties" : {
          "children" : {
              "type" : "nested",
              "include_in_parent" : true
                  }
      }
  }
  </code></pre>
  
  <p>And here is a query, where I want to select a few terms using a match on all children fields query, and a term query: </p>
  
  <pre><code>"query" : {
      "nested": { 
          "path" : "children",
          "query" : {
              "bool" : {
                  "must" : [
                          {"multi_match" : {"query": "value_c_a_1", "fields" : ["children.*"]}},
                          {"term" : {children.field_a : "value_a_1" }}
                      ]
                  }
              }
      } 
  }
  </code></pre>
  
  <p>The above query doesn't work because I can't select all fields in a multimatch query for a nested object. </p>
  
  <pre><code>"query" : {
      "nested": { 
          "path" : "children",
          "query" : {
              "bool" : {
                  "must" : [
                          {"multi_match" : {"query": "value_c_a_1", "fields" : ["*_c_a"]}}
                      ]
                  }
              }
      } 
  }
  </code></pre>
  
  <p>The query above works because the pattern matching allows a * to be placed before a string but not after for some reason (?) </p>
  
  <p><strong>Is there a nice shorthand way to select all the fields of a nested object?</strong></p>
  
  <p>It would also be nice to know why the expected children.* wildcard doesn't work as expected.</p>