andoroperation.md

And / Or operations

• The Utility helper $util.transform.toElasticSearchQueryDSL defaults by AND operation.
• The OR operation can be achieved by using the should clause and minimum_should_match parameter.

The bool query allows you to combine any number of queries into a single query by specifying a query clause that indicates which parts must, should, or must_not match the data in your Elasticsearch index:

• If you specify that part of a bool query must match, only results matching that query (or queries) are returned.
• Specifying that a part of a query should match means that a specified number of the clauses must match for a document to be returned.
• If no must clauses are specified, at least one should clause has to match for the document to be returned.
• Finally, the must_not clause causes matching documents to be excluded from the result set.

must: To combine multiple clauses, use a binary and (query1 AND query2 AND query3).

must_not: Combines multiple clauses with a binary not.

should: Combines multiple clauses with a binary or (query 1 OR query2 OR query3). minimum_should_match parameter number of them should match (defaults to 1 if must is not present and 0 if must is present);

Update schema.graphql

• Update Query type

  type Query {
      andorSearch(
          category: String!
          limit: Int
          nextToken: String
      ): AndOrSearchObjectConnection
  }
  

• Add custom type - SearchableObject

  type AndOrSearchObjectConnection {
      items: [Object]
      nextToken: String
      total: Int
  }
  

Create custom resolver template for AndOrSearch query

• Query.andorSearch.req.vtl

  #set( $indexPath = "/*/doc/_search" )
  {
  "version": "2018-05-29",
  "operation":"GET",
  "path":"$indexPath",
  "params": {
          "body": {
              #if( $context.args.nextToken ) "search_after": [$util.toJson($context.args.nextToken)], #end
              "size": #if( $context.args.limit ) $context.args.limit #else 10 #end,
              "query": {
                  "bool": {
                      "should": [
                          {
                              "bool": {
                                  "must": {
                                      "match": {
                                          "collection_category": "$context.arguments.category"
                                      }
                                  },
                                  "must_not": {
                                      "exists": {
                                          "field": "parent_collection"
                                      }
                                  }
                              }
                          },
                          {
                              "bool": {
                                  "must": {
                                      "match": {
                                          "item_category": "$context.arguments.category"
                                      }
                                  }
                              }
                          }
                      ],
                      "minimum_should_match": 1
                  }
              }
          }
      }
  }
  

• Query.andorSearch.res.vtl

  #set( $es_items = [] )
  #foreach( $entry in $context.result.hits.hits )
  #if( !$foreach.hasNext )
      #set( $nextToken = $entry.sort.get(0) )
  #end
  #foreach ( $mapEntry in $entry.entrySet() )
      #if( $mapEntry.key == "_source" )
      #if( $mapEntry.value.get("collection_category") )
          $util.qr( $mapEntry.value.put("__typename", "Collection") )
      #else
          $util.qr( $mapEntry.value.put("__typename", "Item") )
      #end
      #end
  #end
  $util.qr( $es_items.add($entry.get("_source")) )
  #end
  
  $util.toJson({
  "items": $es_items,
  "total": $ctx.result.hits.total,
  "nextToken": $nextToken
  })
  

Add new resolvers resource in custom stack

"QueryAndorSearchResolver": {
    "Type": "AWS::AppSync::Resolver",
    "Properties": {
        "ApiId": {
        "Ref": "AppSyncApiId"
        },
        "DataSourceName": "ElasticSearchDomain",
        "TypeName": "Query",
        "FieldName": "andorSearch",
        "RequestMappingTemplateS3Location": {
        "Fn::Sub": [
            "s3://${S3DeploymentBucket}/${S3DeploymentRootKey}/resolvers/Query.andorSearch.req.vtl",
            {
            "S3DeploymentBucket": {
                "Ref": "S3DeploymentBucket"
            },
            "S3DeploymentRootKey": {
                "Ref": "S3DeploymentRootKey"
            }
            }
        ]
        },
        "ResponseMappingTemplateS3Location": {
        "Fn::Sub": [
            "s3://${S3DeploymentBucket}/${S3DeploymentRootKey}/resolvers/Query.andorSearch.res.vtl",
            {
            "S3DeploymentBucket": {
                "Ref": "S3DeploymentBucket"
            },
            "S3DeploymentRootKey": {
                "Ref": "S3DeploymentRootKey"
            }
            }
        ]
        }
    }
}