Code + Test

Author: Paultagoras

client-v2/src/main/java/com/clickhouse/client/api/data_formats/internal/AbstractBinaryFormatReader.java

@@ -10,6 +10,8 @@
 import com.clickhouse.client.api.query.POJOSetter;
 import com.clickhouse.client.api.query.QuerySettings;
 import com.clickhouse.data.ClickHouseColumn;
+import com.clickhouse.data.ClickHouseDataType;
+import com.clickhouse.data.ClickHouseEnum;
 import com.clickhouse.data.value.ClickHouseBitmap;
 import com.clickhouse.data.value.ClickHouseGeoMultiPolygonValue;
 import com.clickhouse.data.value.ClickHouseGeoPointValue;
@@ -275,20 +277,19 @@ public String getString(String colName) {
             return null;
         } else if (value instanceof String) {
             return (String) value;
+        } else {
+            ClickHouseDataType dataType = schema.getColumnByName(colName).getDataType();
+            if (dataType == ClickHouseDataType.Enum8 || dataType == ClickHouseDataType.Enum16) {
+                ClickHouseEnum clickHouseEnum = schema.getColumnByName(colName).getEnumConstants();
+                return clickHouseEnum.name(Integer.parseInt(value.toString()));
+            }
         }
         return value.toString();
     }
 
     @Override
     public String getString(int index) {
-        // TODO: it may be incorrect to call .toString() on some objects
-        Object value = readValue(index);
-        if (value == null) {
-            return null;
-        } else if (value instanceof String) {
-            return (String) value;
-        }
-        return value.toString();
+        return getString(schema.columnIndexToName(index));
     }
 
     private <T> T readNumberValue(String colName, NumberConverter.NumberType targetType) {

client-v2/src/test/java/com/clickhouse/client/query/QueryTests.java

@@ -1957,4 +1957,26 @@ public void testReadingSimpleAggregateFunction() throws Exception {
             Assert.assertFalse(reader.hasNext());
         }
     }
+
+    @Test(groups = {"integration"})
+    public void testReadingEnumsAsStrings() throws Exception {
+        final String tableName = "enums_as_strings_test_table";
+        client.execute("DROP TABLE IF EXISTS " + tableName).get();
+        client.execute("CREATE TABLE `" + tableName + "` " +
+                "(idx UInt8, enum1 Enum8('a' = 1, 'b' = 2, 'c' = 3), enum2 Enum16('atch' = 1, 'batch' = 2, 'catch' = 3)) " +
+                "ENGINE Memory").get();
+
+        try (InsertResponse response = client.insert(tableName, new ByteArrayInputStream("1\ta\t2".getBytes(StandardCharsets.UTF_8)), ClickHouseFormat.TSV).get(30, TimeUnit.SECONDS)) {
+            Assert.assertEquals(response.getWrittenRows(), 1);
+        }
+
+        try (QueryResponse queryResponse = client.query("SELECT * FROM " + tableName + " LIMIT 1").get(30, TimeUnit.SECONDS)) {
+            ClickHouseBinaryFormatReader reader = client.newBinaryFormatReader(queryResponse);
+            Assert.assertNotNull(reader.next());
+            Assert.assertEquals(reader.getByte("idx"), Byte.valueOf("1"));
+            Assert.assertEquals(reader.getString("enum1"), "a");
+            Assert.assertEquals(reader.getString("enum2"), "batch");
+            Assert.assertFalse(reader.hasNext());
+        }
+    }
 }