Package com.inductiveautomation.reporting.gateway.api

Interface QuerySource<T extends QueryConfig>

All Known Implementing Classes:

AlarmJournalQuerySource, NamedQuerySource, PrepStmtQuerySource, SimpleSqlQuerySource, TagCalculationQuerySource, TagHistQuerySource

public interface QuerySource<T extends QueryConfig>

A QuerySource executes a type of report query. It must be registered via the GatewayDataSourceRegistry, and also there should be a matching (same ID) QueryConfigFactory registered in the designer.

The QuerySource and QueryConfigFactory share the same string ID, and both deal with the same config object, which must be a subclass of QueryConfig.

Each query source needs to be able to execute some sort of query which returns a Dataset. Top level queries are treated differently than nested queries. This is to give query sources the chance to do special setup and teardown before and after the execution of a group of equivalent nested queries.

Created by carl.gould on 2/3/2015.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	QuerySource.SubQueryTransaction	Used to handle multiple executions of a nested query.

Method Summary

Modifier and Type	Method	Description
QuerySource.SubQueryTransaction	begin(ReportExecutionContext execContext, T queryConfig, Map<String,Object> extraConfigs, QueryResults parent)	Begin a nested query "transaction".
String	getId()	The unique ID for this query source.
Dataset	query(ReportExecutionContext execContext, T queryConfig, Map<String,Object> extraConfigs)	Execute a top level query.

Method Details

getId

String getId()

The unique ID for this query source. Should be qualified with module name first

query

Dataset query(ReportExecutionContext execContext,
 T queryConfig,
 Map<String,Object> extraConfigs)
       throws Exception

Execute a top level query.

Parameters:

execContext - The context for the report being executed.

queryConfig - The config object which was configured in the designer for this query.

extraConfigs - Extra configuration data the designer may need to send. Unused by most data sources, because the queryConfig should contain all data needed to execute the query. May be null.

Returns:

A dataset of results for executing this query

Throws:

Exception

begin

QuerySource.SubQueryTransaction begin(ReportExecutionContext execContext,
 T queryConfig,
 Map<String,Object> extraConfigs,
 QueryResults parent)
                               throws Exception

Begin a nested query "transaction". This means that a nested query (defined by a single query config) is about to be executed, and will probably be executed many times.

Parameters:

execContext - The context for the report being executed

queryConfig - The config object which was configured in designer for this nested query.

extraConfigs - Extra configuration data the designer may need to send. Unused by most data sources, because the queryConfig should contain all data needed to execute the query. May be null.

parent - The QueryResults object for the parent query of this nested query.

Returns:

A new transaction object to handle the execution of this nested query.

Throws:

Exception