diff --git a/public/app/plugins/datasource/cloudwatch/__mocks__/CloudWatchDataSource.ts b/public/app/plugins/datasource/cloudwatch/__mocks__/CloudWatchDataSource.ts
index 5ce973cca66..5b907055215 100644
--- a/public/app/plugins/datasource/cloudwatch/__mocks__/CloudWatchDataSource.ts
+++ b/public/app/plugins/datasource/cloudwatch/__mocks__/CloudWatchDataSource.ts
@@ -49,7 +49,9 @@ export function setupMockedDataSource({
     } as any
   );
   datasource.getVariables = () => ['test'];
-  datasource.getRegions = () => Promise.resolve([]);
+
+  datasource.getNamespaces = jest.fn().mockResolvedValue([]);
+  datasource.getRegions = jest.fn().mockResolvedValue([]);
   const fetchMock = jest.fn().mockReturnValue(of({ data }));
   setBackendSrv({ fetch: fetchMock } as any);
 
diff --git a/public/app/plugins/datasource/cloudwatch/components/MetricsQueryEditor.test.tsx b/public/app/plugins/datasource/cloudwatch/components/MetricsQueryEditor.test.tsx
index 73dd9d21e2b..f74ddbf21d8 100644
--- a/public/app/plugins/datasource/cloudwatch/components/MetricsQueryEditor.test.tsx
+++ b/public/app/plugins/datasource/cloudwatch/components/MetricsQueryEditor.test.tsx
@@ -10,7 +10,7 @@ import { CustomVariableModel, initialVariableModelState } from '../../../../feat
 import { CloudWatchDatasource } from '../datasource';
 import { CloudWatchJsonData, MetricEditorMode, MetricQueryType } from '../types';
 
-import { MetricsQueryEditor, normalizeQuery, Props } from './MetricsQueryEditor';
+import { MetricsQueryEditor, Props } from './MetricsQueryEditor';
 
 const setup = () => {
   const instanceSettings = {
@@ -79,64 +79,6 @@ describe('QueryEditor', () => {
     });
   });
 
-  it('normalizes query on mount', async () => {
-    const { act } = renderer;
-    const props = setup();
-    // This does not actually even conform to the prop type but this happens on initialisation somehow
-    props.query = {
-      queryMode: 'Metrics',
-      apiMode: 'Metrics',
-      refId: '',
-      expression: '',
-      matchExact: true,
-      metricQueryType: MetricQueryType.Search,
-      metricEditorMode: MetricEditorMode.Builder,
-    } as any;
-    await act(async () => {
-      renderer.create(<MetricsQueryEditor {...props} />);
-    });
-    expect((props.onChange as jest.Mock).mock.calls[0][0]).toEqual({
-      namespace: '',
-      metricName: '',
-      expression: '',
-      sqlExpression: '',
-      dimensions: {},
-      region: 'default',
-      id: '',
-      alias: '',
-      statistic: 'Average',
-      period: '',
-      queryMode: 'Metrics',
-      apiMode: 'Metrics',
-      refId: '',
-      matchExact: true,
-      metricQueryType: MetricQueryType.Search,
-      metricEditorMode: MetricEditorMode.Builder,
-    });
-  });
-
-  describe('should use correct default values', () => {
-    it('should normalize query with default values', () => {
-      expect(normalizeQuery({ refId: '42' } as any)).toEqual({
-        namespace: '',
-        metricName: '',
-        expression: '',
-        sqlExpression: '',
-        dimensions: {},
-        region: 'default',
-        id: '',
-        alias: '',
-        statistic: 'Average',
-        matchExact: true,
-        period: '',
-        queryMode: 'Metrics',
-        refId: '42',
-        metricQueryType: MetricQueryType.Search,
-        metricEditorMode: MetricEditorMode.Builder,
-      });
-    });
-  });
-
   describe('should handle editor modes correctly', () => {
     it('when metric query type is metric search and editor mode is builder', async () => {
       await act(async () => {
diff --git a/public/app/plugins/datasource/cloudwatch/components/MetricsQueryEditor.tsx b/public/app/plugins/datasource/cloudwatch/components/MetricsQueryEditor.tsx
index d4884fdeab3..c484dec6cbc 100644
--- a/public/app/plugins/datasource/cloudwatch/components/MetricsQueryEditor.tsx
+++ b/public/app/plugins/datasource/cloudwatch/components/MetricsQueryEditor.tsx
@@ -1,4 +1,4 @@
-import React, { ChangeEvent, PureComponent } from 'react';
+import React, { ChangeEvent, useState } from 'react';
 
 import { QueryEditorProps } from '@grafana/data';
 import { EditorField, EditorRow, Space } from '@grafana/experimental';
@@ -16,181 +16,132 @@ import {
 } from '../types';
 
 import QueryHeader from './QueryHeader';
+import usePreparedMetricsQuery from './usePreparedMetricsQuery';
 
 import { Alias, MathExpressionQueryField, MetricStatEditor, SQLBuilderEditor, SQLCodeEditor } from './';
 
-export type Props = QueryEditorProps<CloudWatchDatasource, CloudWatchQuery, CloudWatchJsonData>;
-
-interface State {
-  sqlCodeEditorIsDirty: boolean;
+export interface Props extends QueryEditorProps<CloudWatchDatasource, CloudWatchQuery, CloudWatchJsonData> {
+  query: CloudWatchMetricsQuery;
 }
 
-export const normalizeQuery = ({
-  namespace,
-  metricName,
-  expression,
-  dimensions,
-  region,
-  id,
-  alias,
-  statistic,
-  period,
-  sqlExpression,
-  metricQueryType,
-  metricEditorMode,
-  ...rest
-}: CloudWatchMetricsQuery): CloudWatchMetricsQuery => {
-  const normalizedQuery = {
-    queryMode: 'Metrics' as const,
-    namespace: namespace ?? '',
-    metricName: metricName ?? '',
-    expression: expression ?? '',
-    dimensions: dimensions ?? {},
-    region: region ?? 'default',
-    id: id ?? '',
-    alias: alias ?? '',
-    statistic: statistic ?? 'Average',
-    period: period ?? '',
-    metricQueryType: metricQueryType ?? MetricQueryType.Search,
-    metricEditorMode: metricEditorMode ?? MetricEditorMode.Builder,
-    sqlExpression: sqlExpression ?? '',
-    ...rest,
-  };
-  return !rest.hasOwnProperty('matchExact') ? { ...normalizedQuery, matchExact: true } : normalizedQuery;
-};
-
-export class MetricsQueryEditor extends PureComponent<Props, State> {
-  state = {
-    sqlCodeEditorIsDirty: false,
-  };
+export const MetricsQueryEditor = (props: Props) => {
+  const { query, onRunQuery, datasource } = props;
+  const [sqlCodeEditorIsDirty, setSQLCodeEditorIsDirty] = useState(false);
+  const preparedQuery = usePreparedMetricsQuery(query, props.onChange);
 
-  componentDidMount = () => {
-    const metricsQuery = this.props.query as CloudWatchMetricsQuery;
-    const query = normalizeQuery(metricsQuery);
-    this.props.onChange(query);
-  };
-
-  onChange = (query: CloudWatchQuery) => {
-    const { onChange, onRunQuery } = this.props;
+  const onChange = (query: CloudWatchQuery) => {
+    const { onChange, onRunQuery } = props;
     onChange(query);
     onRunQuery();
   };
 
-  render() {
-    const { onRunQuery, datasource } = this.props;
-    const metricsQuery = this.props.query as CloudWatchMetricsQuery;
-    const query = normalizeQuery(metricsQuery);
-
-    return (
-      <>
-        <QueryHeader
-          query={query}
-          onRunQuery={onRunQuery}
-          datasource={datasource}
-          onChange={(newQuery) => {
-            if (isCloudWatchMetricsQuery(newQuery) && newQuery.metricEditorMode !== query.metricEditorMode) {
-              this.setState({ sqlCodeEditorIsDirty: false });
-            }
-            this.onChange(newQuery);
-          }}
-          sqlCodeEditorIsDirty={this.state.sqlCodeEditorIsDirty}
-        />
-        <Space v={0.5} />
+  return (
+    <>
+      <QueryHeader
+        query={query}
+        onRunQuery={onRunQuery}
+        datasource={datasource}
+        onChange={(newQuery) => {
+          if (isCloudWatchMetricsQuery(newQuery) && newQuery.metricEditorMode !== query.metricEditorMode) {
+            setSQLCodeEditorIsDirty(false);
+          }
+          onChange(newQuery);
+        }}
+        sqlCodeEditorIsDirty={sqlCodeEditorIsDirty}
+      />
+      <Space v={0.5} />
+
+      {query.metricQueryType === MetricQueryType.Search && (
+        <>
+          {query.metricEditorMode === MetricEditorMode.Builder && (
+            <MetricStatEditor
+              {...props}
+              refId={query.refId}
+              metricStat={query}
+              onChange={(metricStat: MetricStat) => props.onChange({ ...query, ...metricStat })}
+            ></MetricStatEditor>
+          )}
+          {query.metricEditorMode === MetricEditorMode.Code && (
+            <MathExpressionQueryField
+              onRunQuery={onRunQuery}
+              expression={query.expression ?? ''}
+              onChange={(expression) => props.onChange({ ...query, expression })}
+              datasource={datasource}
+            ></MathExpressionQueryField>
+          )}
+        </>
+      )}
+      {query.metricQueryType === MetricQueryType.Query && (
+        <>
+          {query.metricEditorMode === MetricEditorMode.Code && (
+            <SQLCodeEditor
+              region={query.region}
+              sql={query.sqlExpression ?? ''}
+              onChange={(sqlExpression) => {
+                if (!sqlCodeEditorIsDirty) {
+                  setSQLCodeEditorIsDirty(true);
+                }
+                props.onChange({ ...preparedQuery, sqlExpression });
+              }}
+              onRunQuery={onRunQuery}
+              datasource={datasource}
+            />
+          )}
 
-        {query.metricQueryType === MetricQueryType.Search && (
-          <>
-            {query.metricEditorMode === MetricEditorMode.Builder && (
-              <MetricStatEditor
-                {...this.props}
-                refId={query.refId}
-                metricStat={query}
-                onChange={(metricStat: MetricStat) => this.props.onChange({ ...query, ...metricStat })}
-              ></MetricStatEditor>
-            )}
-            {query.metricEditorMode === MetricEditorMode.Code && (
-              <MathExpressionQueryField
+          {query.metricEditorMode === MetricEditorMode.Builder && (
+            <>
+              <SQLBuilderEditor
+                query={query}
+                onChange={props.onChange}
                 onRunQuery={onRunQuery}
-                expression={query.expression ?? ''}
-                onChange={(expression) => this.props.onChange({ ...query, expression })}
                 datasource={datasource}
-              ></MathExpressionQueryField>
-            )}
-          </>
-        )}
-        {query.metricQueryType === MetricQueryType.Query && (
-          <>
-            {query.metricEditorMode === MetricEditorMode.Code && (
-              <SQLCodeEditor
-                region={query.region}
-                sql={query.sqlExpression ?? ''}
-                onChange={(sqlExpression) => {
-                  if (!this.state.sqlCodeEditorIsDirty) {
-                    this.setState({ sqlCodeEditorIsDirty: true });
-                  }
-                  this.props.onChange({ ...metricsQuery, sqlExpression });
-                }}
-                onRunQuery={onRunQuery}
-                datasource={datasource}
-              />
-            )}
-
-            {query.metricEditorMode === MetricEditorMode.Builder && (
-              <>
-                <SQLBuilderEditor
-                  query={query}
-                  onChange={this.props.onChange}
-                  onRunQuery={onRunQuery}
-                  datasource={datasource}
-                ></SQLBuilderEditor>
-              </>
-            )}
-          </>
-        )}
-        <Space v={0.5} />
-        <EditorRow>
-          <EditorField
-            label="ID"
-            width={26}
-            optional
-            tooltip="ID can be used to reference other queries in math expressions. The ID can include numbers, letters, and underscore, and must start with a lowercase letter."
-            invalid={!!query.id && !/^$|^[a-z][a-zA-Z0-9_]*$/.test(query.id)}
-          >
-            <Input
-              id={`${query.refId}-cloudwatch-metric-query-editor-id`}
-              onBlur={onRunQuery}
-              onChange={(event: ChangeEvent<HTMLInputElement>) =>
-                this.onChange({ ...metricsQuery, id: event.target.value })
-              }
-              type="text"
-              value={query.id}
-            />
-          </EditorField>
-
-          <EditorField label="Period" width={26} tooltip="Minimum interval between points in seconds.">
-            <Input
-              id={`${query.refId}-cloudwatch-metric-query-editor-period`}
-              value={query.period || ''}
-              placeholder="auto"
-              onBlur={onRunQuery}
-              onChange={(event: ChangeEvent<HTMLInputElement>) =>
-                this.onChange({ ...metricsQuery, period: event.target.value })
-              }
-            />
-          </EditorField>
-
-          <EditorField
-            label="Alias"
-            width={26}
-            optional
-            tooltip="Change time series legend name using this field. See documentation for replacement variable formats."
-          >
-            <Alias
-              value={metricsQuery.alias ?? ''}
-              onChange={(value: string) => this.onChange({ ...metricsQuery, alias: value })}
-            />
-          </EditorField>
-        </EditorRow>
-      </>
-    );
-  }
-}
+              ></SQLBuilderEditor>
+            </>
+          )}
+        </>
+      )}
+      <Space v={0.5} />
+      <EditorRow>
+        <EditorField
+          label="ID"
+          width={26}
+          optional
+          tooltip="ID can be used to reference other queries in math expressions. The ID can include numbers, letters, and underscore, and must start with a lowercase letter."
+          invalid={!!query.id && !/^$|^[a-z][a-zA-Z0-9_]*$/.test(query.id)}
+        >
+          <Input
+            id={`${query.refId}-cloudwatch-metric-query-editor-id`}
+            onBlur={onRunQuery}
+            onChange={(event: ChangeEvent<HTMLInputElement>) => onChange({ ...preparedQuery, id: event.target.value })}
+            type="text"
+            value={query.id}
+          />
+        </EditorField>
+
+        <EditorField label="Period" width={26} tooltip="Minimum interval between points in seconds.">
+          <Input
+            id={`${query.refId}-cloudwatch-metric-query-editor-period`}
+            value={query.period || ''}
+            placeholder="auto"
+            onBlur={onRunQuery}
+            onChange={(event: ChangeEvent<HTMLInputElement>) =>
+              onChange({ ...preparedQuery, period: event.target.value })
+            }
+          />
+        </EditorField>
+
+        <EditorField
+          label="Alias"
+          width={26}
+          optional
+          tooltip="Change time series legend name using this field. See documentation for replacement variable formats."
+        >
+          <Alias
+            value={preparedQuery.alias ?? ''}
+            onChange={(value: string) => onChange({ ...preparedQuery, alias: value })}
+          />
+        </EditorField>
+      </EditorRow>
+    </>
+  );
+};
diff --git a/public/app/plugins/datasource/cloudwatch/components/PanelQueryEditor.test.tsx b/public/app/plugins/datasource/cloudwatch/components/PanelQueryEditor.test.tsx
new file mode 100644
index 00000000000..eefeca932f7
--- /dev/null
+++ b/public/app/plugins/datasource/cloudwatch/components/PanelQueryEditor.test.tsx
@@ -0,0 +1,133 @@
+import { act, render, screen } from '@testing-library/react';
+import React from 'react';
+
+import { QueryEditorProps } from '@grafana/data';
+
+import { setupMockedDataSource } from '../__mocks__/CloudWatchDataSource';
+import { CloudWatchDatasource } from '../datasource';
+import { CloudWatchQuery, CloudWatchJsonData, MetricEditorMode, MetricQueryType } from '../types';
+
+import { PanelQueryEditor } from './PanelQueryEditor';
+
+// the following three fields are added to legacy queries in the dashboard migrator
+const migratedFields = {
+  statistic: 'Average',
+  metricEditorMode: MetricEditorMode.Builder,
+  metricQueryType: MetricQueryType.Query,
+};
+
+const props: QueryEditorProps<CloudWatchDatasource, CloudWatchQuery, CloudWatchJsonData> = {
+  datasource: setupMockedDataSource().datasource,
+  onRunQuery: jest.fn(),
+  onChange: jest.fn(),
+  query: {} as CloudWatchQuery,
+};
+
+describe('PanelQueryEditor should render right editor', () => {
+  describe('when using grafana 6.3.0 metric query', () => {
+    it('should render the metrics query editor', async () => {
+      const query = {
+        ...migratedFields,
+        dimensions: {
+          InstanceId: 'i-123',
+        },
+        expression: '',
+        highResolution: false,
+        id: '',
+        metricName: 'CPUUtilization',
+        namespace: 'AWS/EC2',
+        period: '',
+        refId: 'A',
+        region: 'default',
+        returnData: false,
+      };
+      await act(async () => {
+        render(<PanelQueryEditor {...props} query={query} />);
+      });
+      expect(screen.getByText('Metric name')).toBeInTheDocument();
+    });
+  });
+
+  describe('when using grafana 7.0.0 style metrics query', () => {
+    it('should render the metrics query editor', async () => {
+      const query = {
+        ...migratedFields,
+        alias: '',
+        apiMode: 'Logs',
+        dimensions: {
+          InstanceId: 'i-123',
+        },
+        expression: '',
+        id: '',
+        logGroupNames: [],
+        matchExact: true,
+        metricName: 'CPUUtilization',
+        namespace: 'AWS/EC2',
+        period: '',
+        queryMode: 'Logs',
+        refId: 'A',
+        region: 'ap-northeast-2',
+        statistics: 'Average',
+      } as any;
+      await act(async () => {
+        render(<PanelQueryEditor {...props} query={query} />);
+      });
+      expect(screen.getByText('Choose Log Groups')).toBeInTheDocument();
+    });
+  });
+
+  describe('when using grafana 7.0.0 style logs query', () => {
+    it('should render the metrics query editor', async () => {
+      const query = {
+        ...migratedFields,
+        alias: '',
+        apiMode: 'Logs',
+        dimensions: {
+          InstanceId: 'i-123',
+        },
+        expression: '',
+        id: '',
+        logGroupNames: [],
+        matchExact: true,
+        metricName: 'CPUUtilization',
+        namespace: 'AWS/EC2',
+        period: '',
+        queryMode: 'Logs',
+        refId: 'A',
+        region: 'ap-northeast-2',
+        statistic: 'Average',
+      } as any;
+      await act(async () => {
+        render(<PanelQueryEditor {...props} query={query} />);
+      });
+      expect(screen.getByText('Log Groups')).toBeInTheDocument();
+    });
+  });
+
+  describe('when using grafana query from curated ec2 dashboard', () => {
+    it('should render the metrics query editor', async () => {
+      const query = {
+        ...migratedFields,
+
+        alias: 'Inbound',
+        dimensions: {
+          InstanceId: '*',
+        },
+        expression:
+          "SUM(REMOVE_EMPTY(SEARCH('{AWS/EC2,InstanceId} MetricName=\"NetworkIn\"', 'Sum', $period)))/$period",
+        id: '',
+        matchExact: true,
+        metricName: 'NetworkOut',
+        namespace: 'AWS/EC2',
+        period: '$period',
+        refId: 'B',
+        region: '$region',
+        statistic: 'Average',
+      } as any;
+      await act(async () => {
+        render(<PanelQueryEditor {...props} query={query} />);
+      });
+      expect(screen.getByText('Metric name')).toBeInTheDocument();
+    });
+  });
+});
diff --git a/public/app/plugins/datasource/cloudwatch/components/PanelQueryEditor.tsx b/public/app/plugins/datasource/cloudwatch/components/PanelQueryEditor.tsx
index 3c9938b98df..079fdae5671 100644
--- a/public/app/plugins/datasource/cloudwatch/components/PanelQueryEditor.tsx
+++ b/public/app/plugins/datasource/cloudwatch/components/PanelQueryEditor.tsx
@@ -1,8 +1,9 @@
 import React, { PureComponent } from 'react';
 
-import { QueryEditorProps, ExploreMode } from '@grafana/data';
+import { QueryEditorProps } from '@grafana/data';
 
 import { CloudWatchDatasource } from '../datasource';
+import { isCloudWatchMetricsQuery } from '../guards';
 import { CloudWatchJsonData, CloudWatchQuery } from '../types';
 
 import LogsQueryEditor from './LogsQueryEditor';
@@ -13,14 +14,13 @@ export type Props = QueryEditorProps<CloudWatchDatasource, CloudWatchQuery, Clou
 export class PanelQueryEditor extends PureComponent<Props> {
   render() {
     const { query } = this.props;
-    const apiMode = query.queryMode ?? 'Metrics';
 
     return (
       <>
-        {apiMode === ExploreMode.Logs ? (
-          <LogsQueryEditor {...this.props} allowCustomValue />
+        {isCloudWatchMetricsQuery(query) ? (
+          <MetricsQueryEditor {...this.props} query={query} />
         ) : (
-          <MetricsQueryEditor {...this.props} />
+          <LogsQueryEditor {...this.props} allowCustomValue />
         )}
       </>
     );
diff --git a/public/app/plugins/datasource/cloudwatch/components/usePreparedMetricsQuery.test.ts b/public/app/plugins/datasource/cloudwatch/components/usePreparedMetricsQuery.test.ts
new file mode 100644
index 00000000000..8f179549d0a
--- /dev/null
+++ b/public/app/plugins/datasource/cloudwatch/components/usePreparedMetricsQuery.test.ts
@@ -0,0 +1,76 @@
+import { renderHook } from '@testing-library/react-hooks';
+
+import { CloudWatchMetricsQuery, MetricEditorMode, MetricQueryType } from '../types';
+
+import usePreparedMetricsQuery, { DEFAULT_QUERY } from './usePreparedMetricsQuery';
+
+interface TestScenario {
+  name: string;
+  query: any;
+  expectedQuery: CloudWatchMetricsQuery;
+}
+
+const baseQuery: CloudWatchMetricsQuery = {
+  refId: 'A',
+  id: '',
+  region: 'us-east-2',
+  namespace: 'AWS/EC2',
+  dimensions: { InstanceId: 'x-123' },
+};
+
+describe('usePrepareMetricsQuery', () => {
+  describe('when an incomplete query is provided', () => {
+    const testTable: TestScenario[] = [
+      { name: 'Empty query', query: { refId: 'A' }, expectedQuery: { ...DEFAULT_QUERY, refId: 'A' } },
+      {
+        name: 'Match exact is not part of the query',
+        query: { ...baseQuery },
+        expectedQuery: { ...DEFAULT_QUERY, ...baseQuery, matchExact: true },
+      },
+      {
+        name: 'Match exact is part of the query',
+        query: { ...baseQuery, matchExact: false },
+        expectedQuery: { ...DEFAULT_QUERY, ...baseQuery, matchExact: false },
+      },
+      {
+        name: 'When editor mode and builder mode different from default is specified',
+        query: { ...baseQuery, metricQueryType: MetricQueryType.Query, metricEditorMode: MetricEditorMode.Code },
+        expectedQuery: {
+          ...DEFAULT_QUERY,
+          ...baseQuery,
+          metricQueryType: MetricQueryType.Query,
+          metricEditorMode: MetricEditorMode.Code,
+        },
+      },
+    ];
+    describe.each(testTable)('scenario %#: $name', (scenario) => {
+      it('should set the default values and trigger onChangeQuery', async () => {
+        const onChangeQuery = jest.fn();
+        const { result } = renderHook(() => usePreparedMetricsQuery(scenario.query, onChangeQuery));
+        expect(onChangeQuery).toHaveBeenLastCalledWith(result.current);
+        expect(result.current).toEqual(scenario.expectedQuery);
+      });
+    });
+  });
+
+  describe('when a complete query is provided', () => {
+    it('should not change the query and should not call onChangeQuery', async () => {
+      const onChangeQuery = jest.fn();
+      const completeQuery: CloudWatchMetricsQuery = {
+        ...baseQuery,
+        expression: '',
+        queryMode: 'Metrics',
+        metricName: '',
+        statistic: 'Sum',
+        period: '300',
+        metricQueryType: MetricQueryType.Query,
+        metricEditorMode: MetricEditorMode.Code,
+        sqlExpression: 'SELECT 1',
+        matchExact: false,
+      };
+      const { result } = renderHook(() => usePreparedMetricsQuery(completeQuery, onChangeQuery));
+      expect(onChangeQuery).not.toHaveBeenCalled();
+      expect(result.current).toEqual(completeQuery);
+    });
+  });
+});
diff --git a/public/app/plugins/datasource/cloudwatch/components/usePreparedMetricsQuery.ts b/public/app/plugins/datasource/cloudwatch/components/usePreparedMetricsQuery.ts
new file mode 100644
index 00000000000..a52d5e277e9
--- /dev/null
+++ b/public/app/plugins/datasource/cloudwatch/components/usePreparedMetricsQuery.ts
@@ -0,0 +1,48 @@
+import deepEqual from 'fast-deep-equal';
+import { useEffect, useMemo } from 'react';
+
+import { CloudWatchMetricsQuery, MetricEditorMode, MetricQueryType } from '../types';
+
+export const DEFAULT_QUERY: Omit<CloudWatchMetricsQuery, 'refId'> = {
+  queryMode: 'Metrics',
+  namespace: '',
+  metricName: '',
+  expression: '',
+  dimensions: {},
+  region: 'default',
+  id: '',
+  statistic: 'Average',
+  period: '',
+  metricQueryType: MetricQueryType.Search,
+  metricEditorMode: MetricEditorMode.Builder,
+  sqlExpression: '',
+  matchExact: true,
+};
+
+const prepareQuery = (query: CloudWatchMetricsQuery) => {
+  const withDefaults = { ...DEFAULT_QUERY, ...query };
+
+  // If we didn't make any changes to the object, then return the original object to keep the
+  // identity the same, and not trigger any other useEffects or anything.
+  return deepEqual(withDefaults, query) ? query : withDefaults;
+};
+
+/**
+ * Returns queries with some defaults + migrations, and calls onChange function to notify if it changes
+ */
+const usePreparedMetricsQuery = (
+  query: CloudWatchMetricsQuery,
+  onChangeQuery: (newQuery: CloudWatchMetricsQuery) => void
+) => {
+  const preparedQuery = useMemo(() => prepareQuery(query), [query]);
+
+  useEffect(() => {
+    if (preparedQuery !== query) {
+      onChangeQuery(preparedQuery);
+    }
+  }, [preparedQuery, query, onChangeQuery]);
+
+  return preparedQuery;
+};
+
+export default usePreparedMetricsQuery;
diff --git a/public/app/plugins/datasource/cloudwatch/guards.ts b/public/app/plugins/datasource/cloudwatch/guards.ts
index 8f7a3f4ea3a..b5346df3c25 100644
--- a/public/app/plugins/datasource/cloudwatch/guards.ts
+++ b/public/app/plugins/datasource/cloudwatch/guards.ts
@@ -6,7 +6,7 @@ export const isCloudWatchLogsQuery = (cloudwatchQuery: CloudWatchQuery): cloudwa
   cloudwatchQuery.queryMode === 'Logs';
 
 export const isCloudWatchMetricsQuery = (cloudwatchQuery: CloudWatchQuery): cloudwatchQuery is CloudWatchMetricsQuery =>
-  cloudwatchQuery.queryMode === 'Metrics';
+  cloudwatchQuery.queryMode === 'Metrics' || !cloudwatchQuery.hasOwnProperty('queryMode'); // in early versions of this plugin, queryMode wasn't defined in a CloudWatchMetricsQuery
 
 export const isCloudWatchAnnotationQuery = (
   cloudwatchQuery: CloudWatchQuery