Spark sql concat example. String manipulation is a common task in data processing.

Spark sql concat example One of its powerful capabilities is concatenating columns, which allows you to combine multiple fields into a single column, creating unified values for analysis Nov 18, 2025 · pyspark. functions module provides string functions to work with strings for manipulation and data processing. concat # pyspark. Concatenation Syntax: 2. spark. Use coalesce to replace the null values with an empty string, and use that for your concat. concat(*cols) [source] # Collection function: Concatenates multiple input columns together into a single column. Key Points- String Manipulation Functions We use string manipulation functions quite extensively. g. Common String Manipulation Functions Example Usage 1. If any of the input strings are null, the resulting concatenation will also be null. concat_ws(sep: str, *cols: ColumnOrName) → pyspark. These functions offer various functionalities for common string operations, such as substring extraction, string concatenation, case conversion, trimming, padding, and pattern matching. Do you know why? Feb 1, 2023 · In Spark SQL, you may want to collect the values of one or more columns into lists after grouping the data by one or more columns. apache. functions , or try the search function . The following examples show how to use each method in practice with the following PySpark DataFrame: from pyspark. col2 in the above statement, its not retaining the order of col2 in mind while concatenating. Handle null values, create formatted strings, and combine arrays in your data transformations. parser. Substring Extraction Syntax: 3. functions provides two functions Aug 8, 2023 · Concatenate columns in Spark Scala using the concat and concat_ws functions. It also contains a list of the available Spark SQL functions. The concat_ws function in PySpark is a powerful tool for concatenating multiple string columns into a single string column, using a specified separator. Below, we explore some of the most useful string manipulation functions and demonstrate how to use them with examples. Aug 12, 2023 · PySpark SQL Functions' concat (~) method concatenates string and array columns. Creating Dataframe for demonstration: Jul 30, 2009 · For example, to match "\abc", a regular expression for regexp can be "^\abc$". functions module and allow you to combine multiple columns, with concat_ws() providing the option to include separators. functions provides two concatenate functions as below concat – It concatenates multiple input columns together into a single column. concat_ws(sep, *cols) [source] # Concatenates multiple input string columns together into a single string column, using the given separator. Column ¶ Concatenates multiple input string columns together into a single string column, using the given separator. […] Feb 7, 2023 · Hive supports several built-in string functions similar to SQL functions to manipulate the strings. Most of the commonly used SQL functions are either part of the PySpark Column class or built-in pyspark. In this article, we shall discuss the concat function and different ways to handle Null values for it. typedLit() provides a way to be explicit about the data type of the constant value being added to a DataFrame, helping to ensure data consistency and type correctness of PySpark workflows. These Hive string functions come in handy when you are doing transformations without bringing data into Spark and using String functions or any equivalent frameworks. Concatenating strings We can pass a variable number of strings to concat function. builder. concat_ws to concatenate the values of the collected list, which will be better than using a udf: Mar 27, 2024 · In this PySpark article, I will explain how to convert an array of String column on DataFrame to a String column (separated or concatenated with a comma, space, or any delimiter character) using PySpark function concat_ws() (translates to concat with separator), and with SQL expression using Scala example. appName(‘students‘). This function allows us to concatenate Using concat () or concat_ws () Spark SQL functions we can concatenate one or more DataFrame columns… When SQL config 'spark. Both concat_ws() and concat () are part of the pyspark. String manipulation is a common task in data processing. By the end, you'll grasp the fundamentals of using GROUP BY for string concatenation and be equipped with practical examples to implement in our projects. 4. This functionality is incredibly useful when you want to merge data from different columns into a unified string representation, with control over how individual values are separated in the pyspark. In order to do this, we will use the groupBy () method in combination with the functions concat_ws (), collect_list () and array_distinct () of PySpark. Understanding how pyspark handles null values can Oct 13, 2014 · I'm experimenting with Spark and Spark SQL and I need to concatenate a value at the beginning of a string field that I retrieve as output from a select (with a join) like the following: val result pyspark. createDataFrame ( [ [&qu Mar 1, 2024 · Learn the syntax of the concat\\_ws function of the SQL language in Databricks SQL and Databricks Runtime. Both these functions return Column type as return type. 4 fails with the error NameError: name 'reduce' is not defined. For example, if the config is enabled, the pattern to match "\abc" should be "\abc". Apr 25, 2024 · Using concat() or concat_ws() Spark SQL functions we can concatenate one or more DataFrame columns into a single column, In this article, you will learn Jul 9, 2022 · Spark SQL - Concatenate w/o Separator (concat_ws and concat) 2022-07-09 spark-sql-function Combining Data with Spark DataFrame Concat Column: A Comprehensive Guide Apache Spark’s DataFrame API is a robust framework for handling large-scale data, offering a structured and efficient way to perform transformations. 6 behavior regarding string literal parsing. Aug 12, 2023 · PySpark SQL Functions' concat_ws (~) method concatenates string-typed columns into a single column with the specified separator. collect_list and concat_ws do the job of LISTAGG, while sort_array is used to output the salary results in a descending order. In this tutorial, we use PySpark program to explain the concatenate functions. ,pyspark. Feb 24, 2023 · To do the same in Databricks, you would add sort_array to the previous Spark SQL example. Below, we’ll explore the most commonly used functions, their syntax, and parameters in Scala, focusing on their application to DataFrame columns. 4, but now there are built-in functions that make combining arrays easy. For example: ('username1', 'friends1, friends2, friends3') I know MySQL does this with GROUP_CONCAT. functions package or SQL expressions. Jul 10, 2025 · PySpark expr() is a SQL function to execute SQL-like expressions and to use an existing DataFrame column value as an expression argument to Pyspark built-in functions. Nov 25, 2023 · Pyspark concat and concat_ws with null values One common data transformation is combining a number of string columns to create a single column. Spark provides union() method in Dataset class to concatenate or append a Dataset to another. functions provides two functions concat () and concat_ws () to concatenate DataFrame multiple columns into a single column. functions import concat_ws, col df = spark. concat_ws # pyspark. Dec 15, 2022 · Concatenate functions in Spark SQL The module pyspark. escapedStringLiterals' that can be used to fallback to the Spark 1. The function works with strings, binary and compatible array columns. also, you will learn how to eliminate the duplicate columns on the result DataFrame. pyspark. PySpark provides a variety of built-in functions for manipulating string columns in DataFrames. Code Examples and explanation of how to use all native Spark String related functions in Spark SQL, Scala and PySpark. The main one is the string_agg function. Note: In other SQL’s, Union eliminates the duplicates but UnionAll combines two datasets including duplicate records. Apr 22, 2024 · Introduction In this tutorial, we will show you how to group and concatenate strings in a PySpark DataFrame. While I am putting df. Jul 23, 2025 · In this article, we'll explore the versatile GROUP BY clause in SQL and how it can be used to concatenate strings efficiently. In many scenarios, you may want to concatenate multiple strings into one. When SQL config 'spark. concat_ws – It concatenates multiple input string columns together into a single string column, with the given separator. Case Conversion and Length Convert Oct 1, 2025 · Learn the syntax of the string\\_agg aggregate function of the SQL language in Databricks SQL and Databricks Runtime. Nov 5, 2025 · When using the concat functionality in Spark Scala to concatenate strings, null values in concat can cause issues. 0. For example I know this works: from pyspark. Examples Oct 10, 2023 · Learn the syntax of the concat\\_ws function of the SQL language in Databricks SQL and Databricks Runtime. You can sign up for our 10 node state of the art cluster/labs to learn Spark SQL using our unique integrated LMS. We focus on common operations for manipulating, transforming, and converting arrays in DataFr Mar 1, 2024 · Learn the syntax of the concat function of the SQL language in Databricks SQL and Databricks Runtime. Jan 9, 2021 · spark-sql> select map_concat(map(1,'a',2,'b',3,'c'),map(4,'d')); map_concat(map(1, a, 2, b, 3, c), map(4, d)) {1:"a",2:"b",3:"c",4:"d"} map\_entries spark-sql> select map_entries(map(1,'a',2,'b',3,'c',4,'d')); map_entries(map(1, a, 2, b, 3, c, 4, d)) [{"key":1,"value":"a"},{"key":2,"value":"b"},{"key":3,"value":"c"},{"key":4,"value":"d Nov 5, 2025 · In this Spark article, I will explain how to convert an array of String column on DataFrame to a String column (separated or concatenated with a comma, space, or any delimiter character) using Spark function concat_ws () (translates to concat with separator), map () transformation and with SQL expression using Scala example. Jun 28, 2022 · It can also be used to concatenate column types string, binary, and compatible array columns. Column ¶ Concatenates multiple input columns together into a single column. Learn about its architecture, functions, and more. concat(*cols: ColumnOrName) → pyspark. Nov 18, 2021 · Hopefully a quick one; Migrating some on-premise SQL views to Databricks and struggling to find conversions for some functions. Collecting a Single Column into a List The following code shows an example of how to collect the values of a single column column3 into a list named list_column3 after grouping the Oct 10, 2023 · Learn the syntax of the concat function of the SQL language in Databricks SQL and Databricks Runtime. Nov 21, 2025 · This blog post dives deep into Spark’s concatenation functions, including concat, concat_ws, and lit, with step-by-step examples, null value handling, and performance best practices. Feb 19, 2024 · This tutorial explains how to concatenate strings from multiple columns in PySpark, including several examples. Oct 30, 2023 · The main approaches for achieving this in PySpark are using the concat () and concat_ws () functions. There is a SQL config 'spark. sql import SparkSession spark = SparkSession. getOrCreate() Apr 1, 2024 · Learn how to use different Spark SQL string functions to manipulate string data with explanations and code examples. functions module. 5. String functions can be applied to string columns or literals to perform various operations such as concatenation, substring extraction, padding, case conversions, and pattern matching with regular expressions. 0” version and replaced with union (). May 5, 2018 · For example, raw dataframe is as follows: +--------+--------+ | col1| col2| +--------+--------+ | null| A| | B| null| | C| D| | null| null| +--------+---- Common String Manipulation Functions Let us go through some of the common string manipulation functions using pyspark as part of this topic. cast (StringType ())) Mar 27, 2024 · PySpark SQL functions lit () and typedLit () are used to add a new column to DataFrame by assigning a literal or constant value. Jul 14, 2025 · This function helps to handle missing data. Concatenating DataFrames using concat () In addition to the methods mentioned above, PySpark also provides the concat() function from the pyspark. New in version 1. Spark’s concat and concat_ws functions, part of the org. This can be accomplished using the collect_list aggregate function in Spark SQL. Keep on passing them as arguments. The following are 7 code examples of pyspark. column. May 20, 2016 · I'm trying to concatenate two PySpark dataframes with some columns that are only on one of them: Jul 10, 2025 · PySpark SQL is a very important and most used module that is used for structured data processing. Oct 20, 2025 · In PySpark, the concat_ws() function is used to concatenate multiple string columns into a single column using a specified separator. Is there any way to do this with Spark SQL? When SQL config 'spark. It allows developers to seamlessly integrate SQL queries with Spark programs, making it easier to work with structured data using the familiar SQL language. Jul 16, 2015 · How do we concatenate two columns in an Apache Spark DataFrame? Is there any function in Spark SQL which we can use? Jul 30, 2009 · For example, to match "\abc", a regular expression for regexp can be "^\abc$". string_agg(field_name, ', ') Oct 13, 2025 · PySpark SQL String Functions PySpark SQL String Functions provide a comprehensive set of functions for manipulating and transforming string data within PySpark DataFrames. functions package, provide scalable solutions for concatenation, operating efficiently across distributed datasets. We use the unionAll() method to concatenate them, resulting in a DataFrame concatenated_df with all the rows from both DataFrames. Some commonly used PySpark SQL String Jun 1, 2020 · If any of the columns in your concat statement are null, the result of the concat is null, that's how it works. It will return one string concatenating all the strings. Let‘s look at a simple example… Quick Example of Concatenating Columns Let‘s say we have a PySpark DataFrame with student details: from pyspark. CONCAT is a SQL function that takes two or more arguments and combines them into a single string. Learn data transformations, string manipulation, and more in the cheat sheet. Home statistics Learning PySpark: A Tutorial on Data Grouping and String Concatenation big data, collect_list, concatenate strings, Data aggregation, Data Manipulation, data processing, dataframe, dataframe operations, groupby, PySpark, python, Spark SQL, SQL Functions, string concatenation Feb 5, 2020 · How to concatenate spark dataframe columns using Spark sql in databricks Asked 5 years, 9 months ago Modified 5 years, 9 months ago Viewed 2k times Jul 23, 2025 · In this article, we are going to see how to concatenate two pyspark dataframe using Python. concat() to concatenate as many columns as you specify in your list. How to Use GROUP BY Clause to Concatenate Strings Mar 27, 2024 · PySpark DataFrame has a join() operation which is used to combine fields from two or multiple DataFrames (by chaining join ()), in this article, you will learn how to do a PySpark Join on Two or Multiple DataFrames by applying conditions on the same or different columns. By default, it throws an exception. Parameters cols Column or str Column names or Column Returns Column A map of merged entries from other maps. Mar 14, 2023 · In Pyspark, string functions can be applied to string columns or literal values to perform various operations, such as concatenation, substring extraction, case conversion, padding, trimming, and Apr 22, 2024 · Spark SQL Function Introduction Spark SQL functions are a set of built-in functions provided by Apache Spark for performing various operations on DataFrame and Dataset objects in Spark SQL. Apr 24, 2024 · In this article, I will explain the usage of the Spark SQL map Feb 28, 2019 · You can use pyspark. Jan 24, 2018 · This example on pyspark/spark 2. sql import SparkSession Jan 22, 2017 · Hi @Assaf, thanks for the clarification. Oct 9, 2019 · I'm sorry I'm not sure I got what you wanted to do but to resolve the issue with getting null values when you concat strings with null values, you only need to assign a data type to your all-null column: input_frame = input_frame. mapKeyDedupPolicy. 6k 26 76 82 Apr 27, 2025 · This document covers techniques for working with array columns and other collection data types in PySpark. It’s a standardized function available in most major database systems, including PostgreSQL, MySQL, SQL Server, and Oracle, ensuring portability across platforms. 47 I have a table of two string type columns (username, friend) and for each username, I want to collect all of its friends on one row, concatenated as strings. In this article, I will explain the differences between concat () and concat_ws () (concat with separator) by examples. Quick Reference guide. Examples Example 1: Basic usage of map_concat Update 2019-06-10: If you wanted your output as a concatenated string, you can use pyspark. In this article, you will learn how to use pyspark. You may also want to check out all available functions/classes of the module pyspark. Nov 25, 2019 · Use concat to concatenate all the columns with the - separator, for which you will need to use lit. If your data is spread across several columns and some values are missing, coalesce() picks the first non-null value, making it easy to create a clean and consolidated column. May 9, 2025 · For the dataset provided earlier, the query will produce: | user_id | result | |---------|-------------| | 1 | 101,102 | | 2 | 201,202 | Problem with Spark SQL: COLLECT_LIST Does Not Maintain Order Initially, you may attempt to use Spark SQL’s COLLECT_LIST to aggregate the coupon IDs: SELECT user_id, CONCAT_WS(',', COLLECT_LIST(CAST(coupon_id AS STRING))) AS result FROM ( SELECT user_id Quick reference for essential PySpark functions with examples. functions. They help with tasks such as cleaning, formatting, and analyzing string These operations were difficult prior to Spark 2. May 4, 2022 · You can groupby the dataframe on CustomerNo and then do a collect list. The function works with strings, numeric, binary and compatible array columns. Following which, you can concat the items of the list of a single column using concat_ws See the code below, Spark DataFrames offer a variety of built-in functions for string manipulation, accessible via the org. lit (None). Nov 14, 2023 · This particular example uses the concat_ws function to concatenate together the strings in the location and name columns into a new column called team, using a space as a separator between the strings. If set to LAST_WIN, it uses the last map’s value. For example, you may want to concatenate “FIRST NAME” & “LAST NAME” of a customer to show his “FULL NAME”. Spark concatenate is used to merge two or more string into one string. Jul 23, 2025 · DataFrame unionAll () – unionAll () is deprecated since Spark “2. Jan 10, 2024 · In the example above, df1 and df2 have duplicate rows. alphabetically sorted, what changes should I make to the statement ? Thanks in Advance ! Mar 17, 2023 · When using the concat functionality in Spark Scala to concatenate strings, null values in concat can cause issues. These functions enable users to manipulate and analyze data within Spark SQL queries, providing a wide range of functionalities similar to those found in traditional SQL databases. Feb 7, 2018 · scala apache-spark apache-spark-sql concatenation edited Jan 23, 2019 at 7:02 Shaido 28. sql. Oct 10, 2025 · In this article, we’ll explore how the concat() function works, how it differs from concat_ws(), and several use cases such as merging multiple columns, adding fixed strings, handling null values, and using it in SQL queries. concat (). Spark SQL String Functions: String functions in Spark SQL are essential for manipulating and transforming text data. if I take the same example as in the question, and need the result as JOHN | PETER, ROBIN, SAM BEN | GRAY, ROSE i,e. PySpark SQL provides a DataFrame API for manipulating data in a distributed and fault-tolerant manner. If it doesn't directly work, you can use cast to change the column types to string, col("column_1"). Nov 6, 2023 · This tutorial explains how to use groupby and concatenate strings in a PySpark DataFrame, including an example. Oct 6, 2025 · pyspark. coalesce() effectively to merge multiple columns into one. Spark SQL provides query-based equivalents for string manipulation, using functions like CONCAT, SUBSTRING, UPPER, LOWER, TRIM, REGEXP_REPLACE, and REGEXP_EXTRACT. functions API, besides these PySpark also supports many other SQL functions, so in order to use these, you have to use Aug 15, 2024 · 1. cast("string") Oct 21, 2024 · Master Spark Functions for Data Engineering Interviews: Learn collect_set, concat_ws, collect_list, explode, and array_union with Examples Jan 3, 2024 · Databricks Spark SQL functions CONCAT_WS In Databricks, the CONCAT_WS function is used to concatenate multiple strings together into a single string, with a specified delimiter (separator) placed … Nov 3, 2023 · This tutorial explains how to add a string to each value in a column of a PySpark DataFrame, including an example. withColumn ('test', sf. Apr 24, 2024 · Spark SQL provides built-in standard Aggregate functions defines in DataFrame API, these come in handy when we need to make aggregate operations on Spark SQL Reference This section covers some key differences between writing Spark SQL data transformations and other types of SQL queries. Jun 25, 2025 · Spark SQL is an open-source distributed computing system designed for big data processing and analytics. For e. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. 0: Supports Spark Connect. Oct 10, 2023 · Learn the syntax of the concat function of the SQL language in Databricks SQL and Databricks Runtime. Dec 28, 2022 · In Pyspark, I want to combine concat_ws and coalesce whilst using the list method. concat ¶ pyspark. ,Using concat_ws () function of Pypsark SQL concatenated three string input columns (firstname, middlename, lastname) into a single string column (Fullname) and separated each column with “_” separator. For example, if the config is enabled, the regexp that can match "\abc" is "^\abc$". . But, in spark both behave an equivalent and use DataFrame duplicate function to get rid of duplicate rows. Notes For duplicate keys in input maps, the handling is governed by spark. escapedStringLiterals' is enabled, it falls back to Spark 1. Changed in version 3. Here are some of the important functions which we typically use. Let us start spark context for this Notebook so that we can execute the code provided. If we have to concatenate literal in between then we have to use lit function. qdnwenx ozal jmopa zuelif engehcih pvieec ghktkk ngznr doara vgn ybebkd ahugghed fwwjhx pmnnhi kobb