feat: add query variable

Author: Femi Novia Lina

src/datasource.ts

@@ -1,11 +1,23 @@
-import { DataSourceInstanceSettings, CoreApp, ScopedVars } from '@grafana/data';
+import { DataSourceInstanceSettings, CoreApp, ScopedVars, VariableSupportType, DataQueryRequest } from '@grafana/data';
 import { DataSourceWithBackend, getTemplateSrv } from '@grafana/runtime';
 
 import { MCQuery, MCConfig, defaultMCSQLQuery } from './types';
+import { SQLEditor } from './components/SQLEditor'
+import { uniqueId } from 'lodash';
 
 export class DataSource extends DataSourceWithBackend<MCQuery, MCConfig> {
   constructor(instanceSettings: DataSourceInstanceSettings<MCConfig>) {
     super(instanceSettings);
+    this.variables = {
+      getType: () => VariableSupportType.Custom,
+      editor: SQLEditor as any,
+      query: (request: DataQueryRequest<MCQuery>) => {
+        const queries = request.targets.map((query) => {
+          return { ...query, refId: query.refId || uniqueId('tempVar') };
+        });
+        return this.query({ ...request, targets: queries });
+      }
+    };
   }
 
   getDefaultQuery(_: CoreApp): Partial<MCQuery> {
@@ -26,6 +38,5 @@ export class DataSource extends DataSourceWithBackend<MCQuery, MCConfig> {
       ...query,
       rawSql: rawQuery
     }
-    
   }
 }