Fix ignored alias for aggregate result in S3 Select (#7849)

The SQL parser as it stands right now ignores alias for aggregate
result, e.g. `SELECT COUNT(*) AS thing FROM s3object` doesn't actually
return record like `{"thing": 42}`, it returns a record like `{"_1": 42}`.
Column alias for aggregate result is supported in AWS's S3 Select, so
this commit fixes that by respecting the `expr.As` in the expression.

Also improve test for S3 select

On top of testing a simple `SELECT` query, we want to test a few more
"advanced" queries (e.g. aggregation).

Convert existing tests into table driven tests[1], and add the new test
cases with "advanced" queries into them.

[1] - https://github.com/golang/go/wiki/TableDrivenTests

pkg/s3select/select_test.go

@@ -48,7 +48,12 @@ func (w *testResponseWriter) Flush() {
 }
 
 func TestCSVInput(t *testing.T) {
-	var requestXML = []byte(`
+	var testTable = []struct {
+		requestXML     []byte
+		expectedResult []byte
+	}{
+		{
+			[]byte(`
 <?xml version="1.0" encoding="UTF-8"?>
 <SelectObjectContentRequest>
     <Expression>SELECT one, two, three from S3Object</Expression>
@@ -67,7 +72,35 @@ func TestCSVInput(t *testing.T) {
         <Enabled>FALSE</Enabled>
     </RequestProgress>
 </SelectObjectContentRequest>
-`)
+`), []byte{
+				0, 0, 0, 137, 0, 0, 0, 85, 194, 213, 168, 241, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 24, 97, 112, 112, 108, 105, 99, 97, 116, 105, 111, 110, 47, 111, 99, 116, 101, 116, 45, 115, 116, 114, 101, 97, 109, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 7, 82, 101, 99, 111, 114, 100, 115, 45, 49, 44, 102, 111, 111, 44, 116, 114, 117, 101, 10, 44, 98, 97, 114, 44, 102, 97, 108, 115, 101, 10, 50, 46, 53, 44, 98, 97, 122, 44, 116, 114, 117, 101, 10, 75, 182, 193, 80, 0, 0, 0, 235, 0, 0, 0, 67, 213, 243, 57, 141, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 8, 116, 101, 120, 116, 47, 120, 109, 108, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 5, 83, 116, 97, 116, 115, 60, 63, 120, 109, 108, 32, 118, 101, 114, 115, 105, 111, 110, 61, 34, 49, 46, 48, 34, 32, 101, 110, 99, 111, 100, 105, 110, 103, 61, 34, 85, 84, 70, 45, 56, 34, 63, 62, 60, 83, 116, 97, 116, 115, 62, 60, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 53, 48, 60, 47, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 60, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 53, 48, 60, 47, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 60, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 51, 54, 60, 47, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 60, 47, 83, 116, 97, 116, 115, 62, 253, 105, 8, 216, 0, 0, 0, 56, 0, 0, 0, 40, 193, 198, 132, 212, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 3, 69, 110, 100, 207, 151, 211, 146,
+			},
+		},
+		{
+			[]byte(`
+<?xml version="1.0" encoding="UTF-8"?>
+<SelectObjectContentRequest>
+    <Expression>SELECT COUNT(*) AS total_record_count from S3Object</Expression>
+    <ExpressionType>SQL</ExpressionType>
+    <InputSerialization>
+        <CompressionType>NONE</CompressionType>
+        <CSV>
+            <FileHeaderInfo>USE</FileHeaderInfo>
+        </CSV>
+    </InputSerialization>
+    <OutputSerialization>
+        <JSON>
+        </JSON>
+    </OutputSerialization>
+    <RequestProgress>
+        <Enabled>FALSE</Enabled>
+    </RequestProgress>
+</SelectObjectContentRequest>
+`), []byte{
+				0, 0, 0, 126, 0, 0, 0, 85, 56, 193, 36, 188, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 24, 97, 112, 112, 108, 105, 99, 97, 116, 105, 111, 110, 47, 111, 99, 116, 101, 116, 45, 115, 116, 114, 101, 97, 109, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 7, 82, 101, 99, 111, 114, 100, 115, 123, 34, 116, 111, 116, 97, 108, 95, 114, 101, 99, 111, 114, 100, 95, 99, 111, 117, 110, 116, 34, 58, 51, 125, 10, 196, 183, 134, 242, 0, 0, 0, 235, 0, 0, 0, 67, 213, 243, 57, 141, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 8, 116, 101, 120, 116, 47, 120, 109, 108, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 5, 83, 116, 97, 116, 115, 60, 63, 120, 109, 108, 32, 118, 101, 114, 115, 105, 111, 110, 61, 34, 49, 46, 48, 34, 32, 101, 110, 99, 111, 100, 105, 110, 103, 61, 34, 85, 84, 70, 45, 56, 34, 63, 62, 60, 83, 116, 97, 116, 115, 62, 60, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 53, 48, 60, 47, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 60, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 53, 48, 60, 47, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 60, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 50, 53, 60, 47, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 60, 47, 83, 116, 97, 116, 115, 62, 47, 153, 24, 28, 0, 0, 0, 56, 0, 0, 0, 40, 193, 198, 132, 212, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 3, 69, 110, 100, 207, 151, 211, 146,
+			},
+		},
+	}
 
 	var csvData = []byte(`one,two,three
 -1,foo,true
@@ -75,11 +108,8 @@ func TestCSVInput(t *testing.T) {
 2.5,baz,true
 `)
 
-	var expectedResult = []byte{
+	for _, testCase := range testTable {
-		0, 0, 0, 137, 0, 0, 0, 85, 194, 213, 168, 241, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 24, 97, 112, 112, 108, 105, 99, 97, 116, 105, 111, 110, 47, 111, 99, 116, 101, 116, 45, 115, 116, 114, 101, 97, 109, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 7, 82, 101, 99, 111, 114, 100, 115, 45, 49, 44, 102, 111, 111, 44, 116, 114, 117, 101, 10, 44, 98, 97, 114, 44, 102, 97, 108, 115, 101, 10, 50, 46, 53, 44, 98, 97, 122, 44, 116, 114, 117, 101, 10, 75, 182, 193, 80, 0, 0, 0, 235, 0, 0, 0, 67, 213, 243, 57, 141, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 8, 116, 101, 120, 116, 47, 120, 109, 108, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 5, 83, 116, 97, 116, 115, 60, 63, 120, 109, 108, 32, 118, 101, 114, 115, 105, 111, 110, 61, 34, 49, 46, 48, 34, 32, 101, 110, 99, 111, 100, 105, 110, 103, 61, 34, 85, 84, 70, 45, 56, 34, 63, 62, 60, 83, 116, 97, 116, 115, 62, 60, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 53, 48, 60, 47, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 60, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 53, 48, 60, 47, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 60, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 51, 54, 60, 47, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 60, 47, 83, 116, 97, 116, 115, 62, 253, 105, 8, 216, 0, 0, 0, 56, 0, 0, 0, 40, 193, 198, 132, 212, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 3, 69, 110, 100, 207, 151, 211, 146,
+		s3Select, err := NewS3Select(bytes.NewReader(testCase.requestXML))
-	}
-
-	s3Select, err := NewS3Select(bytes.NewReader(requestXML))
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -94,13 +124,20 @@ func TestCSVInput(t *testing.T) {
 		s3Select.Evaluate(w)
 		s3Select.Close()
 
-	if !reflect.DeepEqual(w.response, expectedResult) {
+		if !reflect.DeepEqual(w.response, testCase.expectedResult) {
 			t.Fatalf("received response does not match with expected reply")
 		}
+	}
 }
 
 func TestJSONInput(t *testing.T) {
-	var requestXML = []byte(`
+
+	var testTable = []struct {
+		requestXML     []byte
+		expectedResult []byte
+	}{
+		{
+			[]byte(`
 <?xml version="1.0" encoding="UTF-8"?>
 <SelectObjectContentRequest>
     <Expression>SELECT one, two, three from S3Object</Expression>
@@ -119,18 +156,44 @@ func TestJSONInput(t *testing.T) {
         <Enabled>FALSE</Enabled>
     </RequestProgress>
 </SelectObjectContentRequest>
-`)
+`), []byte{
+				0, 0, 0, 137, 0, 0, 0, 85, 194, 213, 168, 241, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 24, 97, 112, 112, 108, 105, 99, 97, 116, 105, 111, 110, 47, 111, 99, 116, 101, 116, 45, 115, 116, 114, 101, 97, 109, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 7, 82, 101, 99, 111, 114, 100, 115, 45, 49, 44, 102, 111, 111, 44, 116, 114, 117, 101, 10, 44, 98, 97, 114, 44, 102, 97, 108, 115, 101, 10, 50, 46, 53, 44, 98, 97, 122, 44, 116, 114, 117, 101, 10, 75, 182, 193, 80, 0, 0, 0, 237, 0, 0, 0, 67, 90, 179, 204, 45, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 8, 116, 101, 120, 116, 47, 120, 109, 108, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 5, 83, 116, 97, 116, 115, 60, 63, 120, 109, 108, 32, 118, 101, 114, 115, 105, 111, 110, 61, 34, 49, 46, 48, 34, 32, 101, 110, 99, 111, 100, 105, 110, 103, 61, 34, 85, 84, 70, 45, 56, 34, 63, 62, 60, 83, 116, 97, 116, 115, 62, 60, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 49, 49, 50, 60, 47, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 60, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 49, 49, 50, 60, 47, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 60, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 51, 54, 60, 47, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 60, 47, 83, 116, 97, 116, 115, 62, 181, 40, 50, 250, 0, 0, 0, 56, 0, 0, 0, 40, 193, 198, 132, 212, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 3, 69, 110, 100, 207, 151, 211, 146,
+			},
+		},
+		{
+			[]byte(`
+<?xml version="1.0" encoding="UTF-8"?>
+<SelectObjectContentRequest>
+    <Expression>SELECT COUNT(*) AS total_record_count from S3Object</Expression>
+    <ExpressionType>SQL</ExpressionType>
+    <InputSerialization>
+        <CompressionType>NONE</CompressionType>
+        <JSON>
+            <Type>DOCUMENT</Type>
+        </JSON>
+    </InputSerialization>
+    <OutputSerialization>
+        <CSV>
+        </CSV>
+    </OutputSerialization>
+    <RequestProgress>
+        <Enabled>FALSE</Enabled>
+    </RequestProgress>
+</SelectObjectContentRequest>
+`), []byte{
+				0, 0, 0, 103, 0, 0, 0, 85, 85, 49, 209, 79, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 24, 97, 112, 112, 108, 105, 99, 97, 116, 105, 111, 110, 47, 111, 99, 116, 101, 116, 45, 115, 116, 114, 101, 97, 109, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 7, 82, 101, 99, 111, 114, 100, 115, 51, 10, 175, 58, 213, 152, 0, 0, 0, 236, 0, 0, 0, 67, 103, 211, 229, 157, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 8, 116, 101, 120, 116, 47, 120, 109, 108, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 5, 83, 116, 97, 116, 115, 60, 63, 120, 109, 108, 32, 118, 101, 114, 115, 105, 111, 110, 61, 34, 49, 46, 48, 34, 32, 101, 110, 99, 111, 100, 105, 110, 103, 61, 34, 85, 84, 70, 45, 56, 34, 63, 62, 60, 83, 116, 97, 116, 115, 62, 60, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 49, 49, 50, 60, 47, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 60, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 49, 49, 50, 60, 47, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 60, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 50, 60, 47, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 60, 47, 83, 116, 97, 116, 115, 62, 52, 192, 77, 114, 0, 0, 0, 56, 0, 0, 0, 40, 193, 198, 132, 212, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 3, 69, 110, 100, 207, 151, 211, 146,
+			},
+		},
+	}
 
 	var jsonData = []byte(`{"three":true,"two":"foo","one":-1}
 {"three":false,"two":"bar","one":null}
 {"three":true,"two":"baz","one":2.5}
 `)
 
-	var expectedResult = []byte{
+	for _, testCase := range testTable {
-		0, 0, 0, 137, 0, 0, 0, 85, 194, 213, 168, 241, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 24, 97, 112, 112, 108, 105, 99, 97, 116, 105, 111, 110, 47, 111, 99, 116, 101, 116, 45, 115, 116, 114, 101, 97, 109, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 7, 82, 101, 99, 111, 114, 100, 115, 45, 49, 44, 102, 111, 111, 44, 116, 114, 117, 101, 10, 44, 98, 97, 114, 44, 102, 97, 108, 115, 101, 10, 50, 46, 53, 44, 98, 97, 122, 44, 116, 114, 117, 101, 10, 75, 182, 193, 80, 0, 0, 0, 237, 0, 0, 0, 67, 90, 179, 204, 45, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 8, 116, 101, 120, 116, 47, 120, 109, 108, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 5, 83, 116, 97, 116, 115, 60, 63, 120, 109, 108, 32, 118, 101, 114, 115, 105, 111, 110, 61, 34, 49, 46, 48, 34, 32, 101, 110, 99, 111, 100, 105, 110, 103, 61, 34, 85, 84, 70, 45, 56, 34, 63, 62, 60, 83, 116, 97, 116, 115, 62, 60, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 49, 49, 50, 60, 47, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 60, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 49, 49, 50, 60, 47, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 60, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 51, 54, 60, 47, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 60, 47, 83, 116, 97, 116, 115, 62, 181, 40, 50, 250, 0, 0, 0, 56, 0, 0, 0, 40, 193, 198, 132, 212, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 3, 69, 110, 100, 207, 151, 211, 146,
-	}
 
-	s3Select, err := NewS3Select(bytes.NewReader(requestXML))
+		s3Select, err := NewS3Select(bytes.NewReader(testCase.requestXML))
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -145,13 +208,20 @@ func TestJSONInput(t *testing.T) {
 		s3Select.Evaluate(w)
 		s3Select.Close()
 
-	if !reflect.DeepEqual(w.response, expectedResult) {
+		if !reflect.DeepEqual(w.response, testCase.expectedResult) {
 			t.Fatalf("received response does not match with expected reply")
 		}
+	}
 }
 
 func TestParquetInput(t *testing.T) {
-	var requestXML = []byte(`
+
+	var testTable = []struct {
+		requestXML     []byte
+		expectedResult []byte
+	}{
+		{
+			[]byte(`
 <?xml version="1.0" encoding="UTF-8"?>
 <SelectObjectContentRequest>
     <Expression>SELECT one, two, three from S3Object</Expression>
@@ -169,8 +239,36 @@ func TestParquetInput(t *testing.T) {
         <Enabled>FALSE</Enabled>
     </RequestProgress>
 </SelectObjectContentRequest>
-`)
+`), []byte{
+				0, 0, 0, 137, 0, 0, 0, 85, 194, 213, 168, 241, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 24, 97, 112, 112, 108, 105, 99, 97, 116, 105, 111, 110, 47, 111, 99, 116, 101, 116, 45, 115, 116, 114, 101, 97, 109, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 7, 82, 101, 99, 111, 114, 100, 115, 45, 49, 44, 102, 111, 111, 44, 116, 114, 117, 101, 10, 44, 98, 97, 114, 44, 102, 97, 108, 115, 101, 10, 50, 46, 53, 44, 98, 97, 122, 44, 116, 114, 117, 101, 10, 75, 182, 193, 80, 0, 0, 0, 235, 0, 0, 0, 67, 213, 243, 57, 141, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 8, 116, 101, 120, 116, 47, 120, 109, 108, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 5, 83, 116, 97, 116, 115, 60, 63, 120, 109, 108, 32, 118, 101, 114, 115, 105, 111, 110, 61, 34, 49, 46, 48, 34, 32, 101, 110, 99, 111, 100, 105, 110, 103, 61, 34, 85, 84, 70, 45, 56, 34, 63, 62, 60, 83, 116, 97, 116, 115, 62, 60, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 45, 49, 60, 47, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 60, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 45, 49, 60, 47, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 60, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 51, 54, 60, 47, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 60, 47, 83, 116, 97, 116, 115, 62, 128, 96, 253, 66, 0, 0, 0, 56, 0, 0, 0, 40, 193, 198, 132, 212, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 3, 69, 110, 100, 207, 151, 211, 146,
+			},
+		},
+		{
+			[]byte(`
+<?xml version="1.0" encoding="UTF-8"?>
+<SelectObjectContentRequest>
+    <Expression>SELECT COUNT(*) AS total_record_count from S3Object</Expression>
+    <ExpressionType>SQL</ExpressionType>
+    <InputSerialization>
+        <CompressionType>NONE</CompressionType>
+        <Parquet>
+        </Parquet>
+    </InputSerialization>
+    <OutputSerialization>
+        <CSV>
+        </CSV>
+    </OutputSerialization>
+    <RequestProgress>
+        <Enabled>FALSE</Enabled>
+    </RequestProgress>
+</SelectObjectContentRequest>
+`), []byte{
+				0, 0, 0, 103, 0, 0, 0, 85, 85, 49, 209, 79, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 24, 97, 112, 112, 108, 105, 99, 97, 116, 105, 111, 110, 47, 111, 99, 116, 101, 116, 45, 115, 116, 114, 101, 97, 109, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 7, 82, 101, 99, 111, 114, 100, 115, 51, 10, 175, 58, 213, 152, 0, 0, 0, 234, 0, 0, 0, 67, 232, 147, 16, 61, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 8, 116, 101, 120, 116, 47, 120, 109, 108, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 5, 83, 116, 97, 116, 115, 60, 63, 120, 109, 108, 32, 118, 101, 114, 115, 105, 111, 110, 61, 34, 49, 46, 48, 34, 32, 101, 110, 99, 111, 100, 105, 110, 103, 61, 34, 85, 84, 70, 45, 56, 34, 63, 62, 60, 83, 116, 97, 116, 115, 62, 60, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 45, 49, 60, 47, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 60, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 45, 49, 60, 47, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 60, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 50, 60, 47, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 60, 47, 83, 116, 97, 116, 115, 62, 190, 146, 162, 21, 0, 0, 0, 56, 0, 0, 0, 40, 193, 198, 132, 212, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 3, 69, 110, 100, 207, 151, 211, 146,
+			},
+		},
+	}
 
+	for _, testCase := range testTable {
 		getReader := func(offset int64, length int64) (io.ReadCloser, error) {
 			testdataFile := "testdata.parquet"
 			file, err := os.Open(testdataFile)
@@ -194,11 +292,7 @@ func TestParquetInput(t *testing.T) {
 			return file, nil
 		}
 
-	var expectedResult = []byte{
+		s3Select, err := NewS3Select(bytes.NewReader(testCase.requestXML))
-		0, 0, 0, 137, 0, 0, 0, 85, 194, 213, 168, 241, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 24, 97, 112, 112, 108, 105, 99, 97, 116, 105, 111, 110, 47, 111, 99, 116, 101, 116, 45, 115, 116, 114, 101, 97, 109, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 7, 82, 101, 99, 111, 114, 100, 115, 45, 49, 44, 102, 111, 111, 44, 116, 114, 117, 101, 10, 44, 98, 97, 114, 44, 102, 97, 108, 115, 101, 10, 50, 46, 53, 44, 98, 97, 122, 44, 116, 114, 117, 101, 10, 75, 182, 193, 80, 0, 0, 0, 235, 0, 0, 0, 67, 213, 243, 57, 141, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 13, 58, 99, 111, 110, 116, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 8, 116, 101, 120, 116, 47, 120, 109, 108, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 5, 83, 116, 97, 116, 115, 60, 63, 120, 109, 108, 32, 118, 101, 114, 115, 105, 111, 110, 61, 34, 49, 46, 48, 34, 32, 101, 110, 99, 111, 100, 105, 110, 103, 61, 34, 85, 84, 70, 45, 56, 34, 63, 62, 60, 83, 116, 97, 116, 115, 62, 60, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 45, 49, 60, 47, 66, 121, 116, 101, 115, 83, 99, 97, 110, 110, 101, 100, 62, 60, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 45, 49, 60, 47, 66, 121, 116, 101, 115, 80, 114, 111, 99, 101, 115, 115, 101, 100, 62, 60, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 51, 54, 60, 47, 66, 121, 116, 101, 115, 82, 101, 116, 117, 114, 110, 101, 100, 62, 60, 47, 83, 116, 97, 116, 115, 62, 128, 96, 253, 66, 0, 0, 0, 56, 0, 0, 0, 40, 193, 198, 132, 212, 13, 58, 109, 101, 115, 115, 97, 103, 101, 45, 116, 121, 112, 101, 7, 0, 5, 101, 118, 101, 110, 116, 11, 58, 101, 118, 101, 110, 116, 45, 116, 121, 112, 101, 7, 0, 3, 69, 110, 100, 207, 151, 211, 146,
-	}
-
-	s3Select, err := NewS3Select(bytes.NewReader(requestXML))
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -211,7 +305,8 @@ func TestParquetInput(t *testing.T) {
 		s3Select.Evaluate(w)
 		s3Select.Close()
 
-	if !reflect.DeepEqual(w.response, expectedResult) {
+		if !reflect.DeepEqual(w.response, testCase.expectedResult) {
 			t.Fatalf("received response does not match with expected reply")
 		}
+	}
 }

pkg/s3select/sql/statement.go

@@ -170,8 +170,12 @@ func (e *SelectStatement) AggregateResult(output Record) error {
 		if err != nil {
 			return err
 		}
+		if expr.As != "" {
+			output.Set(expr.As, v)
+		} else {
 			output.Set(fmt.Sprintf("_%d", i+1), v)
 		}
+	}
 	return nil
 }