若要停止 Spark shell，请按 Ctrl + d 或 Ctrl + z，或者运行命令 quit() 或 exit()（对于 Python），或运行 :q 或 :quit（对于 Scala）。
此简单代码示例查询指定的表，然后显示指定的表的前 5 行。 若要使用其他表，请调整对 spark.read.table 的调用。
from pyspark.sql.session import SparkSession
spark = SparkSession.builder.getOrCreate()
df = spark.read.table("samples.nyctaxi.trips")
df.show(5)
此较长代码示例执行以下操作：
创建内存中数据帧。
在 zzz_demo_temps_table 架构中创建名为 default 的表。 如果已存在同名的表，则先删除该表。 若要使用其他架构或表，请调整对 spark.sql 和/或 temps.write.saveAsTable 的调用。
将数据帧的内容保存到表中。
对表的内容运行 SELECT 查询。
显示查询的结果。
Python语言
from pyspark.sql import SparkSession
from pyspark.sql.types import *
from datetime import date
spark = SparkSession.builder.appName('temps-demo').getOrCreate()
# Create a Spark DataFrame consisting of high and low temperatures
# by airport code and date.
schema = StructType([
StructField('AirportCode', StringType(), False),
StructField('Date', DateType(), False),
StructField('TempHighF', IntegerType(), False),
StructField('TempLowF', IntegerType(), False)
data = [
[ 'BLI', date(2021, 4, 3), 52, 43],
[ 'BLI', date(2021, 4, 2), 50, 38],
[ 'BLI', date(2021, 4, 1), 52, 41],
[ 'PDX', date(2021, 4, 3), 64, 45],
[ 'PDX', date(2021, 4, 2), 61, 41],
[ 'PDX', date(2021, 4, 1), 66, 39],
[ 'SEA', date(2021, 4, 3), 57, 43],
[ 'SEA', date(2021, 4, 2), 54, 39],
[ 'SEA', date(2021, 4, 1), 56, 41]
temps = spark.createDataFrame(data, schema)
# Create a table on the Databricks cluster and then fill
# the table with the DataFrame's contents.
# If the table already exists from a previous run,
# delete it first.
spark.sql('USE default')
spark.sql('DROP TABLE IF EXISTS zzz_demo_temps_table')
temps.write.saveAsTable('zzz_demo_temps_table')
# Query the table on the Databricks cluster, returning rows
# where the airport code is not BLI and the date is later
# than 2021-04-01. Group the results and order by high
# temperature in descending order.
df_temps = spark.sql("SELECT * FROM zzz_demo_temps_table " \
"WHERE AirportCode != 'BLI' AND Date > '2021-04-01' " \
"GROUP BY AirportCode, Date, TempHighF, TempLowF " \
"ORDER BY TempHighF DESC")
df_temps.show()
# Results:
# +-----------+----------+---------+--------+
# |AirportCode| Date|TempHighF|TempLowF|
# +-----------+----------+---------+--------+
# | PDX|2021-04-03| 64| 45|
# | PDX|2021-04-02| 61| 41|
# | SEA|2021-04-03| 57| 43|
# | SEA|2021-04-02| 54| 39|
# +-----------+----------+---------+--------+
# Clean up by deleting the table from the Databricks cluster.
spark.sql('DROP TABLE zzz_demo_temps_table')
Scala(编程语言)
import org.apache.spark.sql.SparkSession
import org.apache.spark.sql.types._
import org.apache.spark.sql.Row
import java.sql.Date
object Demo {
def main(args: Array[String]) {
val spark = SparkSession.builder.master("local").getOrCreate()
// Create a Spark DataFrame consisting of high and low temperatures
// by airport code and date.
val schema = StructType(Array(
StructField("AirportCode", StringType, false),
StructField("Date", DateType, false),
StructField("TempHighF", IntegerType, false),
StructField("TempLowF", IntegerType, false)
val data = List(
Row("BLI", Date.valueOf("2021-04-03"), 52, 43),
Row("BLI", Date.valueOf("2021-04-02"), 50, 38),
Row("BLI", Date.valueOf("2021-04-01"), 52, 41),
Row("PDX", Date.valueOf("2021-04-03"), 64, 45),
Row("PDX", Date.valueOf("2021-04-02"), 61, 41),
Row("PDX", Date.valueOf("2021-04-01"), 66, 39),
Row("SEA", Date.valueOf("2021-04-03"), 57, 43),
Row("SEA", Date.valueOf("2021-04-02"), 54, 39),
Row("SEA", Date.valueOf("2021-04-01"), 56, 41)
val rdd = spark.sparkContext.makeRDD(data)
val temps = spark.createDataFrame(rdd, schema)
// Create a table on the Databricks cluster and then fill
// the table with the DataFrame's contents.
// If the table already exists from a previous run,
// delete it first.
spark.sql("USE default")
spark.sql("DROP TABLE IF EXISTS zzz_demo_temps_table")
temps.write.saveAsTable("zzz_demo_temps_table")
// Query the table on the Databricks cluster, returning rows
// where the airport code is not BLI and the date is later
// than 2021-04-01. Group the results and order by high
// temperature in descending order.
val df_temps = spark.sql("SELECT * FROM zzz_demo_temps_table " +
"WHERE AirportCode != 'BLI' AND Date > '2021-04-01' " +
"GROUP BY AirportCode, Date, TempHighF, TempLowF " +
"ORDER BY TempHighF DESC")
df_temps.show()
// Results:
// +-----------+----------+---------+--------+
// |AirportCode| Date|TempHighF|TempLowF|
// +-----------+----------+---------+--------+
// | PDX|2021-04-03| 64| 45|
// | PDX|2021-04-02| 61| 41|
// | SEA|2021-04-03| 57| 43|
// | SEA|2021-04-02| 54| 39|
// +-----------+----------+---------+--------+
// Clean up by deleting the table from the Databricks cluster.
spark.sql("DROP TABLE zzz_demo_temps_table")
import java.util.ArrayList;
import java.util.List;
import java.sql.Date;
import org.apache.spark.sql.SparkSession;
import org.apache.spark.sql.types.*;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.RowFactory;
import org.apache.spark.sql.Dataset;
public class App {
public static void main(String[] args) throws Exception {
SparkSession spark = SparkSession
.builder()
.appName("Temps Demo")
.config("spark.master", "local")
.getOrCreate();
// Create a Spark DataFrame consisting of high and low temperatures
// by airport code and date.
StructType schema = new StructType(new StructField[] {
new StructField("AirportCode", DataTypes.StringType, false, Metadata.empty()),
new StructField("Date", DataTypes.DateType, false, Metadata.empty()),
new StructField("TempHighF", DataTypes.IntegerType, false, Metadata.empty()),
new StructField("TempLowF", DataTypes.IntegerType, false, Metadata.empty()),
List<Row> dataList = new ArrayList<Row>();
dataList.add(RowFactory.create("BLI", Date.valueOf("2021-04-03"), 52, 43));
dataList.add(RowFactory.create("BLI", Date.valueOf("2021-04-02"), 50, 38));
dataList.add(RowFactory.create("BLI", Date.valueOf("2021-04-01"), 52, 41));
dataList.add(RowFactory.create("PDX", Date.valueOf("2021-04-03"), 64, 45));
dataList.add(RowFactory.create("PDX", Date.valueOf("2021-04-02"), 61, 41));
dataList.add(RowFactory.create("PDX", Date.valueOf("2021-04-01"), 66, 39));
dataList.add(RowFactory.create("SEA", Date.valueOf("2021-04-03"), 57, 43));
dataList.add(RowFactory.create("SEA", Date.valueOf("2021-04-02"), 54, 39));
dataList.add(RowFactory.create("SEA", Date.valueOf("2021-04-01"), 56, 41));
Dataset<Row> temps = spark.createDataFrame(dataList, schema);
// Create a table on the Databricks cluster and then fill
// the table with the DataFrame's contents.
// If the table already exists from a previous run,
// delete it first.
spark.sql("USE default");
spark.sql("DROP TABLE IF EXISTS zzz_demo_temps_table");
temps.write().saveAsTable("zzz_demo_temps_table");
// Query the table on the Databricks cluster, returning rows
// where the airport code is not BLI and the date is later
// than 2021-04-01. Group the results and order by high
// temperature in descending order.
Dataset<Row> df_temps = spark.sql("SELECT * FROM zzz_demo_temps_table " +
"WHERE AirportCode != 'BLI' AND Date > '2021-04-01' " +
"GROUP BY AirportCode, Date, TempHighF, TempLowF " +
"ORDER BY TempHighF DESC");
df_temps.show();
// Results:
// +-----------+----------+---------+--------+
// |AirportCode| Date|TempHighF|TempLowF|
// +-----------+----------+---------+--------+
// | PDX|2021-04-03| 64| 45|
// | PDX|2021-04-02| 61| 41|
// | SEA|2021-04-03| 57| 43|
// | SEA|2021-04-02| 54| 39|
// +-----------+----------+---------+--------+
// Clean up by deleting the table from the Databricks cluster.
spark.sql("DROP TABLE zzz_demo_temps_table");
使用依赖项
通常，主类或 Python 文件将具有其他依赖项 JAR 和文件。 可通过调用 sparkContext.addJar("path-to-the-jar") 或 sparkContext.addPyFile("path-to-the-file") 来添加这类依赖项 JAR 和文件。 还可使用 addPyFile() 接口添加 Egg 文件和 zip 文件。 每次在 IDE 中运行代码时，都会在群集上安装依赖项 JAR 和文件。
Python语言
from lib import Foo
from pyspark.sql import SparkSession
spark = SparkSession.builder.getOrCreate()
sc = spark.sparkContext
#sc.setLogLevel("INFO")
print("Testing simple count")
print(spark.range(100).count())
print("Testing addPyFile isolation")
sc.addPyFile("lib.py")
print(sc.parallelize(range(10)).map(lambda i: Foo(2)).collect())
class Foo(object):
def __init__(self, x):
self.x = x
Python + Java UDF
from pyspark.sql import SparkSession
from pyspark.sql.column import _to_java_column, _to_seq, Column
## In this example, udf.jar contains compiled Java / Scala UDFs:
#package com.example
#import org.apache.spark.sql._
#import org.apache.spark.sql.expressions._
#import org.apache.spark.sql.functions.udf
#object Test {
# val plusOne: UserDefinedFunction = udf((i: Long) => i + 1)
spark = SparkSession.builder \
.config("spark.jars", "/path/to/udf.jar") \
.getOrCreate()
sc = spark.sparkContext
def plus_one_udf(col):
f = sc._jvm.com.example.Test.plusOne()
return Column(f.apply(_to_seq(sc, [col], _to_java_column)))
sc._jsc.addJar("/path/to/udf.jar")
spark.range(100).withColumn("plusOne", plus_one_udf("id")).show()
Scala(编程语言)
package com.example
import org.apache.spark.sql.SparkSession
case class Foo(x: String)
object Test {
def main(args: Array[String]): Unit = {
val spark = SparkSession.builder()
.getOrCreate();
spark.sparkContext.setLogLevel("INFO")
println("Running simple show query...")
spark.read.format("parquet").load("/tmp/x").show()
println("Running simple UDF query...")
spark.sparkContext.addJar("./target/scala-2.11/hello-world_2.11-1.0.jar")
spark.udf.register("f", (x: Int) => x + 1)
spark.range(10).selectExpr("f(id)").show()
println("Running custom objects query...")
val objs = spark.sparkContext.parallelize(Seq(Foo("bye"), Foo("hi"))).collect()
println(objs.toSeq)
访问 Databricks 实用工具
本部分介绍如何使用 Databricks Connect 访问 Databricks 实用工具。
可以使用dbutils.fs和dbutils.secrets实用工具以及Databricks Utilities（dbutils）参考模块。
支持的命令为：dbutils.fs.cp、dbutils.fs.head、dbutils.fs.ls、dbutils.fs.mkdirs、dbutils.fs.mv、dbutils.fs.put、dbutils.fs.rm、dbutils.secrets.getdbutils.secrets.getBytes、dbutils.secrets.list、dbutils.secrets.listScopes。
请参阅文件系统实用程序 (dbutils.fs) 或运行 dbutils.fs.help() 和 机密实用程序 (dbutils.secrets) 或运行 dbutils.secrets.help()。
Python语言
from pyspark.sql import SparkSession
from pyspark.dbutils import DBUtils
spark = SparkSession.builder.getOrCreate()
dbutils = DBUtils(spark)
print(dbutils.fs.ls("dbfs:/"))
print(dbutils.secrets.listScopes())
使用 Databricks Runtime 7.3 LTS 或更高版本时，若要在本地和 Azure Databricks 群集中都能访问 DBUtils 模块，请使用以下 get_dbutils()：
def get_dbutils(spark):
from pyspark.dbutils import DBUtils
return DBUtils(spark)
否则，可以使用以下 get_dbutils()：
def get_dbutils(spark):
if spark.conf.get("spark.databricks.service.client.enabled") == "true":
from pyspark.dbutils import DBUtils
return DBUtils(spark)
else:
import IPython
return IPython.get_ipython().user_ns["dbutils"]
Scala(编程语言)
val dbutils = com.databricks.service.DBUtils
println(dbutils.fs.ls("dbfs:/"))
println(dbutils.secrets.listScopes())
在本地和远程文件系统之间复制文件
可以使用 dbutils.fs 在客户端和远程文件系统之间复制文件。 方案 file:/ 指的是客户端上的本地文件系统。
from pyspark.dbutils import DBUtils
dbutils = DBUtils(spark)
dbutils.fs.cp('file:/home/user/data.csv', 'dbfs:/uploads')
dbutils.fs.cp('dbfs:/output/results.csv', 'file:/home/user/downloads/')
可以传输的最大文件大小为 250 MB。
启用 dbutils.secrets.get
由于安全限制，默认情况下会禁用调用 dbutils.secrets.get 的功能。 请联系 Azure Databricks 支持人员为你的工作区启用此功能。
设置 Hadoop 配置
在客户端上，可使用 spark.conf.set API 设置 Hadoop 配置，该 API 适用于 SQL 和 DataFrame 操作。 在 sparkContext 上设置的 Hadoop 配置必须在群集配置中进行设置或使用笔记本。 这是因为在 sparkContext 上设置的配置没有绑定到用户会话，而是应用于整个群集。
运行 databricks-connect test 以检查连接问题。 本部分描述在使用 Databricks Connect 时可能会遇到的一些常见问题及其解决方法。
本节内容：
Python 版本不匹配
