[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.

4 files changed, 66 insertions, 0 deletions

diff --git a/examples/src/main/java/org/apache/spark/examples/sql/JavaSQLDataSourceExample.java b/examples/src/main/java/org/apache/spark/examples/sql/JavaSQLDataSourceExample.java
index f9087e0593..1860594e8e 100644
--- a/examples/src/main/java/org/apache/spark/examples/sql/JavaSQLDataSourceExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/sql/JavaSQLDataSourceExample.java
@@ -22,6 +22,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 // $example off:schema_merging$
+import java.util.Properties;
 
 // $example on:basic_parquet_example$
 import org.apache.spark.api.java.JavaRDD;
@@ -235,6 +236,8 @@ public class JavaSQLDataSourceExample {
 
   private static void runJdbcDatasetExample(SparkSession 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
     Dataset<Row> jdbcDF = spark.read()
       .format("jdbc")
       .option("url", "jdbc:postgresql:dbserver")
@@ -242,6 +245,24 @@ public class JavaSQLDataSourceExample {
       .option("user", "username")
       .option("password", "password")
       .load();
+
+    Properties connectionProperties = new Properties();
+    connectionProperties.put("user", "username");
+    connectionProperties.put("password", "password");
+    Dataset<Row> 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);
     // $example off:jdbc_dataset$
   }
 }
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"})
     # $example off:jdbc_dataset$
 
 
diff --git a/examples/src/main/r/RSparkSQLExample.R b/examples/src/main/r/RSparkSQLExample.R
index 4e0267a038..373a36dba1 100644
--- a/examples/src/main/r/RSparkSQLExample.R
+++ b/examples/src/main/r/RSparkSQLExample.R
@@ -204,7 +204,11 @@ results <- collect(sql("FROM src SELECT key, value"))
 
 
 # $example on:jdbc_dataset$
+# Loading data from a JDBC source
 df <- read.jdbc("jdbc:postgresql:dbserver", "schema.tablename", user = "username", password = "password")
+
+# Saving data to a JDBC source
+write.jdbc(df, "jdbc:postgresql:dbserver", "schema.tablename", user = "username", password = "password")
 # $example off:jdbc_dataset$
 
 # Stop the SparkSession now
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)
     // $example off:jdbc_dataset$
   }
 }