在PySpark中,你可以使用DataFrame.selectExpr或DataFrame.distinct方法来实现select distinct的功能。以下是这两种方法的语法: 使用DataFrame.selectExpr方法: python df.selectExpr("DISTINCT column1", "column2", ...) 其中,column1, column2, ... 是你想要选择唯一值的列名。 使用DataFrame.distinct方法: ...
logData.createOrReplaceTempView("total_data")然后你就可以 DF=spark.sql("SELECT DISTINCT name,id FROM total_data WHERE app_name!='' AND identifier!='' ")类似这样的查询,注意spark前面声明过,是Session,语句返回的也是一个DataFrame DF.show()可以看一看格式化输出的DF。
如果是服务器的话最好用spark所在的pyspark路径 import os java8_location = r'D:\Java\jdk1.8.0_301/' # 设置你自己的路径 os.environ['JAVA_HOME'] = java8_location from pyspark.sql import SparkSession def get_spark(): # pyspark 读iceberg表 spark...
问将嵌套SELECT转换为PySparkEN版权声明：本文内容由互联网用户自发贡献，该文观点仅代表作者本人。本站仅...
SELECT DISTINCT t1.* FROM table1 t1 JOIN table2 t2 ON t1.column = t2.column; 在这个例子中,使用JOIN可以避免子查询,有时可以提高查询效率。 总结 EXISTS和IN都是检查一个表中的值是否存在于另一个表中的有效方法。选择哪种方法取决于具体的应用场景和性能需求。在处理大数据集时,考虑使用EXISTS和适当的...
Select Rows With Not Null Values in a Column Filter Rows With Not Null Values Using The filter() Method Select Rows With Not Null Values Using the where() Method Select Rows With Not Null Values Using the dropna() Method Filter Rows With Not Null Values using SQL From a PySpark DataFrame...
• Remove duplicates from dataframe, based on two columns A,B, keeping row with max value in another column C • Remove duplicates from a dataframe in PySpark • How to "select distinct" across multiple data frame columns in pandas? • How to find duplicate records in PostgreSQL •...
SQL Select Distinct SQL Where SQL Order by SQL Insert Into SQL AND, OR, and NOT SQL Null Values SQL Update SQL DELETE SQL SELECT TOP SQL MIN and MAX Functions SQL Count(), Avg(), Sum() SQL LIKE SQL Wildcards SQL IN SQL BETWEEN SQL Aliases SQL Joins SQL Inner Join SQL Left Join ...
In this step, first I check the distinct values in each categorical columns between data train and data test. If data train has distinct values more than data test in one or more categorical column, data train and data test will be joined then apply feature engineering on that data combinati...
要创建一个SparkSession,仅仅使用SparkSession.builder 即可:from pyspark.sql import SparkSessionspark_session = SparkSession \.builder \.appName("Python Spark SQL basic example") \.config("spark.some.config.option", "some-value") \.getOrCreate() ...