address comments

Author: gatorsmile

sql/core/src/main/scala/org/apache/spark/sql/DataFrameReader.scala

@@ -159,7 +159,7 @@ class DataFrameReader private[sql](sparkSession: SparkSession) extends Logging {
    * @since 1.4.0
    */
   def jdbc(url: String, table: String, properties: Properties): DataFrame = {
-    // connectionProperties should override settings in extraOptions.
+    // properties should override settings in extraOptions.
     this.extraOptions = this.extraOptions ++ properties.asScala
     // explicit url and dbtable should override all
     this.extraOptions += ("url" -> url, "dbtable" -> table)

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/jdbc/JDBCRelation.scala

@@ -137,7 +137,7 @@ private[sql] case class JDBCRelation(
   }
 
   override def toString: String = {
-    val partitioningInfo = if (parts.nonEmpty) s" [numPartitions=${parts.length}]"
+    val partitioningInfo = if (parts.nonEmpty) s" [numPartitions=${parts.length}]" else ""
     // credentials should not be included in the plan output, table information is sufficient.
     s"JDBCRelation(${jdbcOptions.table})" + partitioningInfo
   }