[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, 19 insertions, 0 deletions

diff --git a/examples/src/main/python/sql/datasource.py b/examples/src/main/python/sql/datasource.py
index b36c901d2b..e9aa9d9ac2 100644
--- a/examples/src/main/python/sql/datasource.py
+++ b/examples/src/main/python/sql/datasource.py
@@ -143,6 +143,8 @@ def json_dataset_example(spark):
 
 def jdbc_dataset_example(spark):
     # $example on:jdbc_dataset$
+    # Note: JDBC loading and saving can be achieved via either the load/save or jdbc methods
+    # Loading data from a JDBC source
     jdbcDF = spark.read \
         .format("jdbc") \
         .option("url", "jdbc:postgresql:dbserver") \
@@ -150,6 +152,23 @@ def jdbc_dataset_example(spark):
         .option("user", "username") \
         .option("password", "password") \
         .load()
+
+    jdbcDF2 = spark.read \
+        .jdbc("jdbc:postgresql:dbserver", "schema.tablename",
+              properties={"user": "username", "password": "password"})
+
+    # 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",
+              properties={"user": "username", "password": "password"})
     # $example off:jdbc_dataset$