Test more string comparison operators

Author: liancheng

sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetFilterSuite.scala

@@ -566,7 +566,14 @@ class ParquetFilterSuite extends QueryTest with ParquetTest with SharedSQLContex
       // scalastyle:off nonascii
       Seq("a", "é").toDF("name").write.parquet(path)
       // scalastyle:on nonascii
+
       assert(spark.read.parquet(path).where("name > 'a'").count() == 1)
+      assert(spark.read.parquet(path).where("name >= 'a'").count() == 2)
+
+      // scalastyle:off nonascii
+      assert(spark.read.parquet(path).where("name < 'é'").count() == 1)
+      assert(spark.read.parquet(path).where("name <= 'é'").count() == 2)
+      // scalastyle:on nonascii
     }
   }
 }