Fix select all from subquery issue

core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/Analyzer.java

@@ -127,7 +127,7 @@ public LogicalPlan visitRelation(Relation node, AnalysisContext context) {
   @Override
   public LogicalPlan visitRelationSubquery(RelationSubquery node, AnalysisContext context) {
     LogicalPlan subquery = analyze(node.getChild().get(0), context);
-    context.push();
+    // inherit the parent environment to keep the subquery fields in current environment
     TypeEnvironment curEnv = context.peek();
 
     // Put subquery alias in index namespace so the qualifier can be removed

core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/dsl/AstDSL.java

@@ -17,6 +17,7 @@
 
 import com.amazon.opendistroforelasticsearch.sql.ast.expression.AggregateFunction;
 import com.amazon.opendistroforelasticsearch.sql.ast.expression.Alias;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.AllFields;
 import com.amazon.opendistroforelasticsearch.sql.ast.expression.And;
 import com.amazon.opendistroforelasticsearch.sql.ast.expression.Argument;
 import com.amazon.opendistroforelasticsearch.sql.ast.expression.Case;
@@ -263,6 +264,10 @@ public static UnresolvedArgument unresolvedArg(String argName, UnresolvedExpress
     return new UnresolvedArgument(argName, argValue);
   }
 
+  public AllFields allFields() {
+    return AllFields.of();
+  }
+
   public Field field(UnresolvedExpression field) {
     return new Field((QualifiedName) field);
   }

core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalyzerTest.java

@@ -391,7 +391,7 @@ public void window_function() {
   /**
    * SELECT name FROM (
    *   SELECT name, age FROM test
-   * ) AS a.
+   * ) AS schema.
    */
   @Test
   public void from_subquery() {
@@ -418,6 +418,33 @@ public void from_subquery() {
     );
   }
 
+  /**
+   * SELECT * FROM (
+   *   SELECT name FROM test
+   * ) AS schema.
+   */
+  @Test
+  public void select_all_from_subquery() {
+    assertAnalyzeEqual(
+        LogicalPlanDSL.project(
+            LogicalPlanDSL.project(
+                LogicalPlanDSL.relation("schema"),
+                DSL.named("string_value", DSL.ref("string_value", STRING))),
+            DSL.named("string_value", DSL.ref("string_value", STRING))
+        ),
+        AstDSL.project(
+            AstDSL.relationSubquery(
+                AstDSL.project(
+                    AstDSL.relation("schema"),
+                    AstDSL.alias("string_value", AstDSL.qualifiedName("string_value"))
+                ),
+                "schema"
+            ),
+            AstDSL.allFields()
+        )
+    );
+  }
+
   /**
    * SELECT name, AVG(age) FROM test GROUP BY name.
    */

integ-test/src/test/resources/correctness/bugfixes/901.txt

@@ -0,0 +1,3 @@
+SELECT * FROM (SELECT Origin, Dest, AvgTicketPrice FROM kibana_sample_data_flights) AS flights
+SELECT * FROM (SELECT Origin AS origin FROM kibana_sample_data_flights) AS flights
+SELECT * FROM (SELECT * FROM (SELECT Origin FROM kibana_sample_data_flights) AS flights) AS f

integ-test/src/test/resources/correctness/queries/subquries.txt

@@ -16,4 +16,5 @@ SELECT Origin, Dest FROM (SELECT * FROM kibana_sample_data_flights WHERE AvgTick
 SELECT Origin, MIN(AvgTicketPrice) FROM (SELECT * FROM kibana_sample_data_flights) AS flights GROUP BY Origin ORDER BY MAX(AvgTicketPrice)
 SELECT Origin FROM (SELECT Origin, AvgTicketPrice FROM kibana_sample_data_flights) AS flights GROUP BY Origin HAVING MIN(AvgTicketPrice) > 500
 SELECT avg_price FROM (SELECT AVG(AvgTicketPrice) AS avg_price FROM kibana_sample_data_flights) AS flights
-SELECT Dest FROM (SELECT Dest, OriginWeather FROM (SELECT Dest, OriginWeather, AvgTicketPrice FROM (SELECT Dest, Origin, OriginWeather, AvgTicketPrice FROM kibana_sample_data_flights WHERE Origin = 'Zurich Airport') AS flights_data WHERE AvgTicketPrice < 10000) AS flights WHERE OriginWeather = 'Clear') AS f
+SELECT Dest FROM (SELECT Dest, OriginWeather FROM (SELECT Dest, OriginWeather, AvgTicketPrice FROM (SELECT Dest, Origin, OriginWeather, AvgTicketPrice FROM kibana_sample_data_flights WHERE Origin = 'Zurich Airport') AS flights_data WHERE AvgTicketPrice < 10000) AS flights WHERE OriginWeather = 'Clear') AS f
+SELECT * FROM (SELECT Origin FROM kibana_sample_data_flights) AS flights