df1 = spark.sql("select * from emp") df2 = spark.sql("select * from dept") df3 = df1.join(df2,df1.deptno == df2.deptno,'right').select(df1.empno,df1.ename,df2.dname,df2.loc).show() 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 测试记录...
conn = sqlalchemy.create_engine('mysql+pymysql://用户名:密码@IP/数据库名?charset='数据库编码') da = pd.read_sql("SELECT * FROM 表名;",conn) #双引号里可以放入sql语句 Ps:若是类似LIKE '%文字%' 的结构,则需要改成LIKE '%%文字%%' # 写入 pd.io.sql.to_sql(dataframe, '表名', conn...
Selecting rows(行), columns(列) 代码语言:javascript 代码运行次数:0 复制Cloud Studio 代码运行 # Create the SparkDataFrame df <- as.DataFrame(faithful) # 获取关于 SparkDataFrame 基础信息 df ## SparkDataFrame[eruptions:double, waiting:double] # Select only the "eruptions" column head(select(df,...
创建SparkContext对象:conf = SparkConf().setAppName("Python Spark").setMaster("local") sc = SparkContext(conf=conf) 创建一个包含数据的RDD:data = [("John", 25, "USA"), ("Alice", 30, "Canada"), ("Bob", 35, "UK")] rdd = sc.parallelize(data) 定义要写入文本文件的列:columns_t...
( SELECT pkg,cate1_gp AS cate FROM con_tabl3 ) ) b ON a.pkg=b.pkg ) GROUP BY gazj )";// 待解析 SQL// 新建 Parser// 解析 SQL 语句List<SQLStatement> stmtList = SQLUtils.parseStatements(selectSql,"hive");// 遍历解析结果,根据不同的语句类型做相应的处理for(SQLStatement stmt : ...
select count(Ship City) from DB Table Input-1 count(DISTINCTExpression 1[,Expression2]): Returns the number of rows with different non-null expression values. You can use the statement inSpark SQLto obtain the number of unique non-null values of theShip Cityfield, as shown in the following...
'${hiveconf:accessKeyId}', access.key.secret = '${hiveconf:accessKeySecret}', table.name = 'test_table', instance.name = 'test_instance', catalog = '{"columns":{"pk":{"col":"pk","type":"string"},"data":{"col":"data","type":"string"}}}' ); select * from test_...
github.spark_redshift_community.spark.redshift OPTIONS ( dbtable 'my_table', tempdir 's3n://path/for/temp/data' url 'jdbc:redshift://redshifthost:5439/database?user=username&password=pass' ) AS SELECT * FROM tabletosave;Note that the SQL API only supports the creation of new tables ...
catalog.listColumns("smart")) name description dataType nullable isPartition isBucket email null string true false false iq null bigint true false false name null string true false false 6. 访问底层的SparkContext SparkSession.sparkContext 返回底层的 SparkContext,用于创建 RDD 以及管理集群资源。
Similar to the Scala API forColumns, many of the operator functions could be ported over. For example: dataset.select( col("colA")+5) dataset.select( col("colA")/col("colB") ) dataset.where( col("colA") `===`6)//or alternativelydataset.where( col("colA") eq6) ...