added python sql example

Author: jyotiska

examples/src/main/python/sql.py

@@ -0,0 +1,52 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+import sys
+
+from pyspark import SparkContext
+from pyspark.sql import SQLContext
+
+
+if __name__ == "__main__":
+    if len(sys.argv) != 2:
+        print >> sys.stderr, "Usage: sql <file>"
+        exit(-1)
+    sc = SparkContext(appName="PythonWordCount")
+    sqlContext = SQLContext(sc)
+
+    # A JSON dataset is pointed to by path.
+    # The path can be either a single text file or a directory storing text files.
+    path = "examples/src/main/resources/people.json"
+    # Create a SchemaRDD from the file(s) pointed to by path
+    people = sqlContext.jsonFile(path)
+
+    # The inferred schema can be visualized using the printSchema() method.
+    people.printSchema()
+    # root
+    #  |-- age: IntegerType
+    #  |-- name: StringType
+
+    # Register this SchemaRDD as a table.
+    people.registerAsTable("people")
+
+    # SQL statements can be run by using the sql methods provided by sqlContext.
+    teenagers = sqlContext.sql("SELECT name FROM people WHERE age >= 13 AND age <= 19")
+
+    for each in teenagers.collect():
+        print each[0]
+
+    sc.stop()