[SPARK-14525][SQL] Make DataFrameWrite.save work for jdbc

## What changes were proposed in this pull request?

This change modifies the implementation of DataFrameWriter.save such that it works with jdbc, and the call to jdbc merely delegates to save.

## How was this patch tested?

This was tested via unit tests in the JDBCWriteSuite, of which I added one new test to cover this scenario.

## Additional details

rxin This seems to have been most recently touched by you and was also commented on in the JIRA.

This contribution is my original work and I license the work to the project under the project's open source license.

Author: Justin Pihony <justin.pihony@gmail.com>
Author: Justin Pihony <justin.pihony@typesafe.com>

Closes #12601 from JustinPihony/jdbc_reconciliation.

1 files changed, 22 insertions, 0 deletions

diff --git a/examples/src/main/scala/org/apache/spark/examples/sql/SQLDataSourceExample.scala b/examples/src/main/scala/org/apache/spark/examples/sql/SQLDataSourceExample.scala
index dc3915a488..66f7cb1b53 100644
--- a/examples/src/main/scala/org/apache/spark/examples/sql/SQLDataSourceExample.scala
+++ b/examples/src/main/scala/org/apache/spark/examples/sql/SQLDataSourceExample.scala
@@ -16,6 +16,8 @@
  */
 package org.apache.spark.examples.sql
 
+import java.util.Properties
+
 import org.apache.spark.sql.SparkSession
 
 object SQLDataSourceExample {
@@ -148,6 +150,8 @@ object SQLDataSourceExample {
 
   private def runJdbcDatasetExample(spark: SparkSession): Unit = {
     // $example on:jdbc_dataset$
+    // Note: JDBC loading and saving can be achieved via either the load/save or jdbc methods
+    // Loading data from a JDBC source
     val jdbcDF = spark.read
       .format("jdbc")
       .option("url", "jdbc:postgresql:dbserver")
@@ -155,6 +159,24 @@ object SQLDataSourceExample {
       .option("user", "username")
       .option("password", "password")
       .load()
+
+    val connectionProperties = new Properties()
+    connectionProperties.put("user", "username")
+    connectionProperties.put("password", "password")
+    val jdbcDF2 = spark.read
+      .jdbc("jdbc:postgresql:dbserver", "schema.tablename", connectionProperties)
+
+    // Saving data to a JDBC source
+    jdbcDF.write
+      .format("jdbc")
+      .option("url", "jdbc:postgresql:dbserver")
+      .option("dbtable", "schema.tablename")
+      .option("user", "username")
+      .option("password", "password")
+      .save()
+
+    jdbcDF2.write
+      .jdbc("jdbc:postgresql:dbserver", "schema.tablename", connectionProperties)
     // $example off:jdbc_dataset$
   }
 }