SQL: Fix JdbcPreparedStatementIT.testDatetimeWithNanos (#107629)

Fixes #105677

x-pack/plugin/sql/qa/jdbc/src/main/java/org/elasticsearch/xpack/sql/qa/jdbc/PreparedStatementTestCase.java

@@ -163,7 +163,7 @@ public void testDatetimeWithNanos() throws IOException, SQLException {
             versionSupportsDateNanos()
         );
 
-        long randomTimestampWitnNanos = randomTimeInNanos();
+        long randomTimestampWitnNanos = randomTimestampWithNanos();
         int randomNanosOnly = extractNanosOnly(randomTimestampWitnNanos);
         setupIndexForDateTimeTestsWithNanos(randomTimestampWitnNanos);
 
@@ -195,7 +195,7 @@ public void testDateTimeWithNanosAgainstDriverWithoutSupport() throws IOExceptio
             versionSupportsDateNanos()
         );
 
-        long randomTimestampWitnNanos = randomTimeInNanos();
+        long randomTimestampWitnNanos = randomTimestampWithNanos();
         int randomNanosOnly = extractNanosOnly(randomTimestampWitnNanos);
         setupIndexForDateTimeTestsWithNanos(randomTimestampWitnNanos);
 
@@ -218,6 +218,14 @@ public void testDateTimeWithNanosAgainstDriverWithoutSupport() throws IOExceptio
         }
     }
 
+    private static long randomTimestampWithNanos() {
+        long randomTimestampWithNanos = randomTimeInNanos();
+        // Indexing will jiggle the value by adding -1, 0, 1. The query will truncate it from ns to ms and expect no match. If the
+        // jiggled value will round to no sub-ms fraction, the query will match. So ensure that won't happen.
+        randomTimestampWithNanos += (randomTimestampWithNanos % 1_000_000 < 10) ? 10 : 0;
+        return randomTimestampWithNanos;
+    }
+
     public void testDate() throws IOException, SQLException {
         long randomMillis = randomLongBetween(1, DateUtils.MAX_MILLIS_BEFORE_9999);
         setupIndexForDateTimeTests(randomMillis);