clear query and window on datasource selection

Signed-off-by: Shenoy Pratik <sgguruda@amazon.com>

common/constants/index.ts

@@ -89,6 +89,7 @@ export const ACCELERATION_INDEX_NAME_INFO = `All OpenSearch acceleration indices
 - All user given index names must be in lowercase letters. Index name cannot begin with underscores. Spaces, commas, and characters -, :, ", *, +, /, \, |, ?, #, >, or < are not allowed.  
   `;
 
+export const OPENSEARCH_SQL_INIT_QUERY = `SHOW tables LIKE '%';`;
 export const TIMESTAMP_DATATYPE = 'timestamp';
 export const FETCH_OPENSEARCH_INDICES_PATH = '/api/sql_console/sqlquery';
 export const POLL_INTERVAL_MS = 2000;

public/components/Main/main.tsx

@@ -25,6 +25,7 @@ import { ChromeBreadcrumb, CoreStart } from '../../../../../src/core/public';
 import {
   ASYNC_QUERY_ENDPOINT,
   ASYNC_QUERY_JOB_ENDPOINT,
+  OPENSEARCH_SQL_INIT_QUERY,
   POLL_INTERVAL_MS,
 } from '../../../common/constants';
 import { AsyncQueryLoadingStatus } from '../../../common/types';
@@ -239,7 +240,7 @@ export class Main extends React.Component<MainProps, MainState> {
     this.onChange = this.onChange.bind(this);
     this.state = {
       language: 'SQL',
-      sqlQueriesString: "SHOW tables LIKE '%';",
+      sqlQueriesString: OPENSEARCH_SQL_INIT_QUERY,
       pplQueriesString: '',
       queries: [],
       queryTranslations: [],
@@ -816,8 +817,11 @@ export class Main extends React.Component<MainProps, MainState> {
   }
 
   handleDataSelect = (selectedItems: EuiComboBoxOptionOption[]) => {
-    if (selectedItems[0].label !== 'OpenSearch' && this.state.language === 'SQL') {
-      this.updateSQLQueries('');
+    this.updateSQLQueries('');
+    this.updatePPLQueries('');
+    this.onClear();
+    if (selectedItems[0].label === 'OpenSearch' && this.state.language === 'SQL') {
+      this.updateSQLQueries(OPENSEARCH_SQL_INIT_QUERY);
     }
     this.setState({
       selectedDatasource: selectedItems,