SQL Expressions: Exclude CTEs from required Tables (#106479)

Fixes #105030

---------

Co-authored-by: Sam Jewell <2903904+samjewell@users.noreply.github.com>

pkg/registry/apis/query/parser.go

@@ -167,14 +167,8 @@ func (p *queryParser) parseRequest(ctx context.Context, input *query.QueryDataRe
 				q, ok := queryRefIDs[refId]
 
 				if !ok {
-					_, isSQLCMD := target.Command.(*expr.SQLCommand)
-					if isSQLCMD {
-						continue
-					} else {
-						target, ok = expressions[refId]
-						if !ok {
-							return rsp, makeDependencyError(exp.RefID, refId)
-						}
+					if target, ok = expressions[refId]; !ok {
+						return rsp, makeDependencyError(exp.RefID, refId)
 					}
 				}
 

pkg/registry/apis/query/parser_test.go

@@ -201,6 +201,46 @@ func TestSqlInputs(t *testing.T) {
 	require.Equal(t, parsedRequestInfo.SqlInputs["B"], struct{}{})
 }
 
+func TestSqlCTE(t *testing.T) {
+	parser := newQueryParser(
+		expr.NewExpressionQueryReader(featuremgmt.WithFeatures(featuremgmt.FlagSqlExpressions)),
+		nil,
+		tracing.InitializeTracerForTest(),
+		log.NewNopLogger(),
+	)
+
+	parsedRequestInfo, err := parser.parseRequest(context.Background(), &query.QueryDataRequest{
+		QueryDataRequest: data.QueryDataRequest{
+			Queries: []data.DataQuery{
+				data.NewDataQuery(map[string]any{
+					"refId": "A",
+					"datasource": &data.DataSourceRef{
+						Type: "prometheus",
+						UID:  "local-prom",
+					},
+				}),
+				data.NewDataQuery(map[string]any{
+					"refId": "B",
+					"datasource": &data.DataSourceRef{
+						Type: "__expr__",
+						UID:  "__expr__",
+					},
+					"type": "sql",
+					"expression": `WITH CTE AS (
+						SELECT
+							Month
+						FROM A
+						)
+
+						SELECT * FROM CTE`,
+				}),
+			},
+		},
+	})
+	require.NoError(t, err)
+	require.Equal(t, parsedRequestInfo.SqlInputs["B"], struct{}{})
+}
+
 func TestGrafanaDS(t *testing.T) {
 	ctx := context.Background()
 	parser := newQueryParser(expr.NewExpressionQueryReader(featuremgmt.WithFeatures()),