com.conveyal.gtfs.graphql.fetchers

Class RowCountFetcher

java.lang.Object

com.conveyal.gtfs.graphql.fetchers.RowCountFetcher

All Implemented Interfaces:

graphql.schema.DataFetcher

public class RowCountFetcher
extends Object
implements graphql.schema.DataFetcher

Get quantity of rows in the given table.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RowCountFetcher.GroupCount The convenience object corresponding to the groupCountType GraphQL type.

Field Summary

Fields

Modifier and Type	Field and Description
static graphql.schema.GraphQLObjectType	groupCountType This is very similar to an GraphQLGtfsSchema.errorCountType, but is used for counts of entities grouped by some column.
static org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor and Description
RowCountFetcher(String tableName)
RowCountFetcher(String tableName, String filterField)
RowCountFetcher(String tableName, String filterField, String groupByField)

Method Summary

Modifier and Type	Method and Description
static graphql.schema.GraphQLFieldDefinition	field(String tableName) For cases where the GraphQL field name is the same as the table name itself.
static graphql.schema.GraphQLFieldDefinition	field(String fieldName, String tableName) Convenience method to create a field in a GraphQL schema that fetches the number of rows in a table.
static graphql.schema.GraphQLFieldDefinition	field(String fieldName, String tableName, String filterField) Convenience method to create a field in a GraphQL schema that fetches the number of rows in a table with a filter or where clause.
Object	get(graphql.schema.DataFetchingEnvironment environment)
static graphql.schema.GraphQLFieldDefinition	groupedField(String tableName, String groupByColumn) A GraphQL field used to deliver lists of group counts.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOG

public static final org.slf4j.Logger LOG

groupCountType

public static graphql.schema.GraphQLObjectType groupCountType

This is very similar to an GraphQLGtfsSchema.errorCountType, but is used for counts of entities grouped by some column. It is defined here to ensure that it is statically initialized before its use below.

Constructor Detail

RowCountFetcher

public RowCountFetcher(String tableName)

RowCountFetcher

public RowCountFetcher(String tableName,
                       String filterField)

RowCountFetcher

public RowCountFetcher(String tableName,
                       String filterField,
                       String groupByField)

Method Detail

get

public Object get(graphql.schema.DataFetchingEnvironment environment)

Specified by:

get in interface graphql.schema.DataFetcher

field

public static graphql.schema.GraphQLFieldDefinition field(String fieldName,
                                                          String tableName)

Convenience method to create a field in a GraphQL schema that fetches the number of rows in a table. Must be on a type that has a "namespace" field for context.

field

public static graphql.schema.GraphQLFieldDefinition field(String fieldName,
                                                          String tableName,
                                                          String filterField)

Convenience method to create a field in a GraphQL schema that fetches the number of rows in a table with a filter or where clause. If a filter field is provided, count only the rows that match the parent entity's value for the given field. For example, adding a trip_count field to routes (filter field route_id) would add a trip count to each route entity with the number of trips that operate under each route's route_id.

field

public static graphql.schema.GraphQLFieldDefinition field(String tableName)

For cases where the GraphQL field name is the same as the table name itself.

groupedField

public static graphql.schema.GraphQLFieldDefinition groupedField(String tableName,
                                                                 String groupByColumn)

A GraphQL field used to deliver lists of group counts. Currently the primary use of this field is for delivering trip counts grouped by either service_id, pattern_id, or route_id. These quantities can also be filtered by providing a string value for pattern_id