Update changelog

Author: shati-patel

extensions/ql-vscode/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## [UNRELEASED]
 
+- Add a command _CodeQL: Run Query on Multiple Databases_, which lets users select multiple databases to run a query on. [#898](https://github.com/github/vscode-codeql/pull/898)
+
 ## 1.5.2 - 13 July 2021
 
 - Add the _Add Database Source to Workspace_ command to the right-click context menu in the databases view. This lets users re-add a database's source folder to the workspace and browse the source code. [#891](https://github.com/github/vscode-codeql/pull/891)

extensions/ql-vscode/src/extension.ts

@@ -472,14 +472,14 @@ async function activateWithInstalledDistribution(
   ): Promise<void> {
     if (qs !== undefined) {
       // If no databaseItem is specified, use the database currently selected in the Databases UI
-      const dbItem = databaseItem || await databaseUI.getDatabaseItem(progress, token);
-      if (dbItem === undefined) {
+      databaseItem = databaseItem || await databaseUI.getDatabaseItem(progress, token);
+      if (databaseItem === undefined) {
         throw new Error('Can\'t run query without a selected database');
       }
       const info = await compileAndRunQueryAgainstDatabase(
         cliServer,
         qs,
-        dbItem,
+        databaseItem,
         quickEval,
         selectedQuery,
         progress,