Fix PostgreSQL proxy timestamp text output adding trailing .0

Fixes #37437

Author: daguimu

database/protocol/dialect/postgresql/src/main/java/org/apache/shardingsphere/database/protocol/postgresql/packet/command/query/PostgreSQLDataRowPacket.java

@@ -30,6 +30,9 @@
 import java.nio.charset.StandardCharsets;
 import java.sql.SQLException;
 import java.sql.SQLXML;
+import java.sql.Timestamp;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
 import java.util.Collection;
 
 /**
@@ -79,13 +82,34 @@ private void writeTextValue(final PostgreSQLPacketPayload payload, final Object
             byte[] columnData = ((Boolean) each ? "t" : "f").getBytes(payload.getCharset());
             payload.writeInt4(columnData.length);
             payload.writeBytes(columnData);
+        } else if (each instanceof Timestamp) {
+            byte[] columnData = formatTimestamp((Timestamp) each).getBytes(payload.getCharset());
+            payload.writeInt4(columnData.length);
+            payload.writeBytes(columnData);
         } else {
             byte[] columnData = each.toString().getBytes(payload.getCharset());
             payload.writeInt4(columnData.length);
             payload.writeBytes(columnData);
         }
     }
 
+    private String formatTimestamp(final Timestamp timestamp) {
+        LocalDateTime dateTime = timestamp.toLocalDateTime();
+        int nanos = dateTime.getNano();
+        if (0 == nanos) {
+            return dateTime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
+        }
+        int micros = nanos / 1000;
+        StringBuilder result = new StringBuilder(dateTime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.")));
+        result.append(String.format("%06d", micros));
+        int length = result.length();
+        while (result.charAt(length - 1) == '0') {
+            length--;
+        }
+        result.setLength(length);
+        return result.toString();
+    }
+
     private byte[] encodeByteaText(final byte[] value) {
         byte[] result = new byte[value.length * 2 + 2];
         result[0] = '\\';

database/protocol/dialect/postgresql/src/test/java/org/apache/shardingsphere/database/protocol/postgresql/packet/command/query/PostgreSQLDataRowPacketTest.java

@@ -33,6 +33,7 @@
 import java.nio.charset.StandardCharsets;
 import java.sql.SQLException;
 import java.sql.SQLXML;
+import java.sql.Timestamp;
 import java.util.Collections;
 import java.util.stream.Stream;
 
@@ -140,6 +141,10 @@ private static Stream<Arguments> textValueCases() {
         return Stream.of(
                 Arguments.of("boolean_true", true, "t".getBytes(StandardCharsets.UTF_8)),
                 Arguments.of("boolean_false", false, "f".getBytes(StandardCharsets.UTF_8)),
-                Arguments.of("string_value", "value", "value".getBytes(StandardCharsets.UTF_8)));
+                Arguments.of("string_value", "value", "value".getBytes(StandardCharsets.UTF_8)),
+                Arguments.of("timestamp_no_fractional", Timestamp.valueOf("1973-06-03 10:30:01"), "1973-06-03 10:30:01".getBytes(StandardCharsets.UTF_8)),
+                Arguments.of("timestamp_with_fractional", Timestamp.valueOf("2024-01-15 14:30:45.123"), "2024-01-15 14:30:45.123".getBytes(StandardCharsets.UTF_8)),
+                Arguments.of("timestamp_trailing_zeros_stripped", Timestamp.valueOf("2024-01-15 14:30:45.120"), "2024-01-15 14:30:45.12".getBytes(StandardCharsets.UTF_8)),
+                Arguments.of("timestamp_microsecond_precision", Timestamp.valueOf("2024-01-15 14:30:45.123456"), "2024-01-15 14:30:45.123456".getBytes(StandardCharsets.UTF_8)));
     }
 }