com.conveyal.gtfs.graphql.fetchers

Class JDBCFetcher

java.lang.Object

com.conveyal.gtfs.graphql.fetchers.JDBCFetcher

All Implemented Interfaces:

graphql.schema.DataFetcher<List<Map<String,Object>>>

public class JDBCFetcher
extends Object
implements graphql.schema.DataFetcher<List<Map<String,Object>>>

A generic fetcher to get fields out of an SQL database table.

Field Summary

Fields

Modifier and Type	Field and Description
static String	DATE_ARG
static String	FROM_ARG
static String	ID_ARG
static String	LIMIT_ARG
static org.slf4j.Logger	LOG
static String	MAX_LAT
static String	MAX_LON
static String	MIN_LAT
static String	MIN_LON
static String	OFFSET_ARG
static String	SEARCH_ARG
String	tableName
static String	TO_ARG

Constructor Summary

Constructors

Constructor and Description
JDBCFetcher(String tableName) Constructor for tables that need neither restriction by a where clause nor sorting based on the enclosing entity.
JDBCFetcher(String tableName, String parentJoinField)
JDBCFetcher(String tableName, String parentJoinField, String sortField, boolean autoLimit)
JDBCFetcher(String tableName, String parentJoinField, String sortField, boolean autoLimit, String childJoinField)

Method Summary

Modifier and Type	Method and Description
static graphql.schema.GraphQLFieldDefinition	field(String tableName)
List<Map<String,Object>>	get(graphql.schema.DataFetchingEnvironment environment)
static void	validateNamespace(String namespace) Checks that the namespace argument is clean and meets the SQL schema specifications.

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

ID_ARG

public static final String ID_ARG

See Also:

Constant Field Values

LIMIT_ARG

public static final String LIMIT_ARG

See Also:

Constant Field Values

OFFSET_ARG

public static final String OFFSET_ARG

See Also:

Constant Field Values

SEARCH_ARG

public static final String SEARCH_ARG

See Also:

Constant Field Values

DATE_ARG

public static final String DATE_ARG

See Also:

Constant Field Values

FROM_ARG

public static final String FROM_ARG

See Also:

Constant Field Values

TO_ARG

public static final String TO_ARG

See Also:

Constant Field Values

MIN_LAT

public static final String MIN_LAT

See Also:

Constant Field Values

MIN_LON

public static final String MIN_LON

See Also:

Constant Field Values

MAX_LAT

public static final String MAX_LAT

See Also:

Constant Field Values

MAX_LON

public static final String MAX_LON

See Also:

Constant Field Values

tableName

public final String tableName

Constructor Detail

JDBCFetcher

public JDBCFetcher(String tableName)

Constructor for tables that need neither restriction by a where clause nor sorting based on the enclosing entity. These would typically be at the topmost level, directly inside a feed rather than nested in some GTFS entity type.

JDBCFetcher

public JDBCFetcher(String tableName,
                   String parentJoinField)

Parameters:

tableName - the database table from which to fetch rows.

parentJoinField - The field in the enclosing level of the Graphql query to use in a where clause. This allows e.g. selecting all the stop_times within a trip, using the enclosing trip's trip_id. If null, no such clause is added.

JDBCFetcher

public JDBCFetcher(String tableName,
                   String parentJoinField,
                   String sortField,
                   boolean autoLimit)

Parameters:

sortField - The field on which to sort the list or fetched rows (in ascending order only). If null, no sort is included.

autoLimit - Whether to by default apply a limit to the fetched rows. This is used for certain tables that it is unnatural to expect a limit (e.g., shape points or pattern stops).

JDBCFetcher

public JDBCFetcher(String tableName,
                   String parentJoinField,
                   String sortField,
                   boolean autoLimit,
                   String childJoinField)

Parameters:

childJoinField - The child table field that should be joined to the parent join field. This enables joining where references from the child table to the parent table do not share the same field name, e.g., stops#stop_id -> transfers#from_stop_id. This value defaults to parentJoinField if argument is null.

Method Detail

field

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

get

public List<Map<String,Object>> get(graphql.schema.DataFetchingEnvironment environment)

Specified by:

get in interface graphql.schema.DataFetcher<List<Map<String,Object>>>

validateNamespace

public static void validateNamespace(String namespace)

Checks that the namespace argument is clean and meets the SQL schema specifications.

Parameters:

namespace - database schema namespace/table prefix