Presto group by concat. The worst feeling when you overlook the simple solution.
Presto group by concat. Also discussed example on MySQL GROUP_CONCAT() function, GROUP_CONCAT() with order by and example, GROUP_CONCAT() with distinct, GROUP_CONCAT() with separator. chr (n) -> varchar() Returns the Unicode code point n as a single character string. : SELECT some_expression(a) FROM GROUP BY some_expression(a) Also, you can refer to SELECT clause columns using their position in the SELECT list: SELECT some_expression(a) FROM GROUP BY 1 This is ANSI SQL standard syntax. map_union(x (K, V)) → Sep 15, 2020 · Another option that avoids using filter is to create an array for each label and then concatenate them all together. 5% of May 6, 2021 · フィールドを結合したかったので、MySQLではCONCAT関数を使うのが分かり試したら動きませんでした。 CONCAT関数と同じことをPrestoで実行したかったのですが、調べても出てこなったため、職場のエンジニアに聞いた事をアウトプットします。 やりたいこと 我是Presto的新手，希望获得与MySQL中的group_concat函数相同的功能。下面两个是等价的吗？如果没有，对如何在Presto中重新创建group_concat功能有什么建议吗？MySQL：select a, group_concat(b separator ',')from tablegroup by aPresto：select a, array_join(array_ I want to apply some sort of concatenation of the strings in a column using groupby. In Presto, you cannot use SELECT clause column aliases in the GROUP BY clause. See GROUP_CONCAT for more details and how to change max length. This is my code so far: import pandas as pd from io import StringIO data = StringIO(""" "na Presto equivalent of MySQL group_concat I'm new to Presto and looking to get the same functionality as the group_concat function in MySQL. 4k 收藏 10 点赞数 7 Jun 27, 2019 · Optimizing Queries with a Single Aggregation Function Over DISTINCT Presto has an optimization for queries with only a single aggregation function, aggregating over DISTINCT. Jul 13, 2020 · I'm looking for a function in Presto to concat two columns with a separator like underline. Dec 24, 2023 · An occasional issue in presto is with users trying to create arrays with more than 200 elements. LISTAGG supports DISTINCT and provides an ON OVERFLOW clause to control the behavior when exceeding the maximum string length. However, you can achieve the same result using the array_agg and array_join functions in Presto. CONCAT To append multiple f Aug 29, 2023 · Presto doesn't have a built-in GROUP_CONCAT function like some other database systems do. Think of it as a reference flag post for people interested in a quick lookup for advanced analytics functions and operators used in modern data lake operations based on Presto. 3k次。本文介绍了如何使用MySQL的GROUP_CONCAT函数，Hive的concat_ws和collect_list以及Presto的array_join和array_agg函数，将表中的life字段合并为每个name的完整一天记录。 We would like to show you a description here but the site won’t allow us. This optimizer is available behind the optimizer. Are the following two equivalent? If not, any suggestions for how I can recreate the group_concat 在 Presto中的分组聚合查询流程中介绍了Presto中的HashAgg的大体流程，本文对Presto中的Agg再次进行更进一步的介绍。Group By操作是分析型数据库中非常重要的一个操作，在分布式计算系统中又有着特殊的实现，这和… This type of problem is solved easily on MySQL with its GROUP_CONCAT() aggregate function, but solving it on Microsoft SQL Server is more awkward. List of functions and operators # [] substring operator || concatenation operator < comparison operator > comparison operator <= comparison operator >= comparison Jun 24, 2025 · The Power of String Aggregation When working with relational databases, we often need to combine multiple row values into a single string - whether for reporting, data transformation, or simplifying application logic. Thank you Array functions # all_match(array (T), function (T, boolean))→boolean # Returns whether all elements of an array match the given predicate. This function provides the same functionality as the SQL-standard concatenation operator (||). db_test. Amperity segments are built The GROUP_CONCAT() aggregate function is the MySQL version of the standard SQL LISTAGG function, to concatenate aggregate data into a string. If this can be achieved, what is a good approach to move forward with the implementation of this logic? Additionally, the functions operate on Unicode code points and not user visible characters (or grapheme clusters). 4k次。博客提及了MySQL、Hive和Presto三种信息技术相关内容，还给出了参考官网，涉及聚合函数、数组函数和运算符等方面。 If all records inside the group are NULL, or if the group is empty, the function returns NULL. It is particularly useful for aggregating summaries, such as combining related information into a single field for better readability or reporting. Unlike standard aggregation functions that return numerical results (like SUM() or AVG()), GROUP_CONCAT() specializes in Jan 27, 2024 · The GROUP_CONCAT() function in MySQL is a powerful tool when working with aggregations. Since we can count the cardinality during analysis, simply split and concat it to make life easy for This tutorial shows you how to use the MySQL GROUP_CONCAT function to concatenate strings from a group with various options. codepoint (string) -> integer() Returns the Unicode code point of the only character of string. Are the following two equivalent? If not, any suggestions for how I can recreate the group_concat The GROUP_CONCAT () function in MySQL is used to concatenate data from multiple rows into one field. g. String functions Aug 18, 2024 · student. To eliminate duplicate values, use the DISTINCT clause. How to Use GROUP BY Clause to Concatenate Strings We would like to show you a description here but the site won’t allow us. This is evaluated for each row before it is used in the aggregation and is supported for all aggregate functions. 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. io/answers/presto-equivalent-of-mysql-group_concat Aggregate Functions Overview General Aggregate Functions Bitwise Aggregate Functions Map Aggregate Functions Approximate Aggregate Functions Statistical Aggregate Functions Classification Metrics Aggregate Functions Differential Entropy Functions Reservoir Sample Functions Noisy Aggregate Functions Overview Aggregate functions operate on a set of values to compute a single result. The LIKE statement can be used for pattern matching and is documented in Pattern comparison: LIKE. optimize-single-distinct configuration in older versions of Presto. It's similar to the other answer above, but note that in Presto (and standard SQL), if any of the arguments to the || operator is NULL, the result is NULL. How to concatenate arrays grouped by another column in Presto?Is this possible in SQL (preferably Presto): I want to reshape I'm new to Presto and looking to get the same functionality as the group_concat function in MySQL. 0 BY-SA版权 文章标签： #Mysql中的group_concat在Presto和Redshift #group_concat presto MySql 专栏收录该内容 14 篇文章 订阅专栏 MySQL group_concat的Presto等效函数 MySQL中的group_concat函数可以将多行数据合并成一行，并在每个值之间用指定的分隔符分隔。 但是，在Presto中没有直接等效的函数。 在本文中，我们将介绍如何使用Presto来实现MySQL中group_concat的等效函数。 Nov 12, 2024 · CC 4. How Reliable is Trino (Presto) Trino (Presto) transfers the data through the network. Jul 11, 2024 · MySQL GROUP_CONCAT() function returns a string with concatenated non-NULL value from a group. Here's an example query that demonstrates how to concatenate values from a column for each group: SELECT group_id, array_join(array_agg(value), ',') AS concatenated_values FROM your_table GROUP BY group_id String functions and operators String operators The || operator performs concatenation. Jul 30, 2025 · 文章浏览阅读3k次。文章展示了如何在不同数据库系统（Presto,Hive,MySQL）中，通过SQL查询将参与人的名字按照项目名以逗号合并，主要用于数据聚合和报告生成。 Oct 27, 2020 · Presto has powerful array functions. txt数据 张三 10 北京 男 喝酒 李四 20 北京 男 抽烟 王五 30 北京 女 烫头 赵六 40 上海 男 抽烟 麻七 50 上海 女 烫头 在presto中计算 分解式 按照城市分组 统计人数 select city, count (1) as cnt from hive. Any ideas in how to do this? Sep 20, 2022 · I Have a table like and want to insert an additional column by joining data from multiple rows an d columns. Aug 27, 2020 · I want the output to be one concat string with comma like: 2156, 6781, 3145, 1235, 9874 So far I export the table and using python to do it. Jan 18, 2022 · AWS athena (presto SQL): How to take the (set-like) union of arrays in a group by statement Asked 3 years, 7 months ago Modified 2 years ago Viewed 3k times Jun 29, 2022 · The concat_ws () function adds two or more strings together with a separator. Presto中group by的执行计划 下图呈现的这个计划图，就是一个presto的逻辑执行计划 Jul 11, 2025 · The GROUP_CONCAT () function in MySQL is an aggregation function that combines data from multiple rows into a single string. Feb 3, 2022 · You are looking for LISTAGG () or GROUP_CONCAT () that typically exist in relational databases. This should work: select array_distinct(flatten(array_agg(pets))) all_pets from mytable Basically this aggregates all arrays to together, as an array of arrays, then concatenates all elements together in a single array, and finally removes duplicates. Filtering during aggregation The FILTER keyword can be used to remove rows from aggregation processing with a condition expressed using a WHERE clause. I need to find a string concatenation function in AWS Glue inside GROUP BY, so far tried SELECT CONCAT('wo', 'rd'); for which I need concatenation inside GROUP BY, written in meta language: SELECT Jul 3, 2020 · If you want to count the number of articles for each tag you want to run a query like SELECT tag, COUNT(*) FORM articles GROUP BY tag, but if what you have is a tags array you can’t. Are the following two equivalent? If not, any suggestions for how I can recreate the group_concat functionality in Presto? MySQL: select a, group_concat (b separator ',') from table group by a Presto: select a, array_join (array_agg (b), ',') from table group by a (Found this as a suggested Nov 12, 2024 · CC 4. See example at ahana. SQL Presto CONCAT_WS函数的用法和等效函数介绍 在本文中，我们将介绍Presto查询引擎中的CONCAT_WS函数以及其在SQL中的等效函数。 阅读更多：SQL 教程 CONCAT_WS函数简介 在Presto中，CONCAT_WS函数是一种字符串操作函数，用于将多个字符串连接在一起，同时使用指定的分隔符将它们分隔开。CONCAT_WS函数的语法 Apr 19, 2021 · 原始数据集如下： group by语法 对数据集进行聚合操作，主要是通过group by子句实现，如下（按照name，对每个人的id进行汇总）： 但是当希望在一段sql语法中，实现较复杂的聚合操作，则可以通过presto中的GROUPING SETS，CUBE和ROLLUP语法实现。 chr (n) -> varchar() Returns the Unicode code point n as a single character string. This function provides the Feb 26, 2024 · presto支持group_concat 偷代码的猫 于 2024-02-26 14:14:29 发布 阅读量1. To sort values in the result, use the ORDER BY clause. Why should you use this reference? ¶ The SQL Segment Editor in the Queries and Segment tabs uses Presto SQL as the underlying SQL engine. The Queries and Segments pages use Presto to return query results and audience segments. 0 BY-SA版权 文章标签： #Mysql中的group_concat在Presto和Redshift #group_concat presto MySql 专栏收录该内容 14 篇文章 订阅专栏 We would like to show you a description here but the site won’t allow us. It enables the creation of a concatenated string result from a group of rows. 简介 ### 1. This is an aggregate (GROUP BY) function which returns a String value, if the group contains at least one non-NULL value. In mysql, use SELECT id, GROUP_CONCAT(data) FROM yourtable GROUP BY id or use your custom separator: SELECT id, GROUP_CONCAT(data SEPARATOR ', ') FROM yourtable GROUP BY id NOTE: The result is truncated to the maximum length that is given by the group_concat_max_len system variable, which has a default value of 1024. Map aggregate functions histogram(x) → map<K,bigint> Returns a map containing the count of the number of times each input value occurs. This is where MySQL’s GROUP_CONCAT() function shines. Mar 14, 2024 · 本文探讨了在Hive和Presto中如何使用collect_set和array_agg聚合函数收集不重复的订单ID，并通过concat_ws和array_join函数以逗号分隔连接成字符串。示例展示了在SQL查询中进行数据去重和数组连接的基本步骤，对于大数据处理和分析具有实际应用价值。. Trino (Presto) is designed for faster query processing when compared to Hive, so it sacrifices fault-tolerance, to some extent. See the following SO question for help: "How to get multiple records against one record based on relation?" Presto跟Mysql和Hive有一些区别，有的函数是 各自独有 的。 列转行的实现方法如下： 在mysql中使用 group_concat 在Hive中使用 concat_ws 和 collect_list Presto可以使用 array_agg 和 array_join，替代上述的功能。 array_agg 函数会返回一个当前列的数组 array_join 将数组转换为字符串 Jul 28, 2016 · Mysqlのgroup_concatをPrestoとRedshiftで書く際に毎回混乱するのでメモ Mysql select a, group_concat(b separator ',') from table group by a Presto sele 上边这条sql语句涉及到一个比较简单的group by操作，首先对数据进行过滤，过滤条件是“orderkey <1000”，然后对筛选出的数据，根据returnflag进行分组，对每一个分组内的数据计算count、累加total_price、对tax求平均。 3. Apr 5, 2025 · Presto equivalent of MySQL group_concat I'm new to Presto and looking to get the same functionality as the group_concat function in MySQL. Some languages combine multiple code points into a single user-perceived character, the basic unit of a writing system for a language, but the functions will treat each code point as a separate unit. It requires at least two arguments, and uses the first argument to separate all following arguments. 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. Aug 8, 2022 · When you enter your query in the SQL Editor or create a calculation, you use Presto SQL syntax. Are the following two equivalent? If not, any suggestions for how I can recreate the group_concat sql mysql presto group-concat trino Mike Moyer 501 asked May 23, 2017 at 18:23 0votes 3answers 114views Jan 11, 2024 · 文章浏览阅读161次。# 1. ends_with Mar 27, 2019 · I know some basics of Presto and can join columns based on conditions but was not sure if this can be achieved with query. Aug 27, 2019 · This post is a lot different from our earlier entries. Are the following two equivalent? If not, any suggestions for how I can recreate the group_concat sql mysql presto group-concat trino Mike Moyer 501 asked May 23, 2017 at 18:23 0votes 1answer 4kviews I think in using COUNT (DISTINCT (hash)) OVER (PARTITION BY colA), but as far as I know, COUNT (DISTINCT ()) is not allowed as a window function in Presto. Using UNNEST you pivot the hierarchical data model into a flat model that the relational model understands. concat (string1, , stringN) -> varchar() Returns the concatenation of string1, string2, , stringN. Learn how to concatenate strings and arrays in Athena queries. May 8, 2024 · Expected Behavior assertQuery ("SELECT id, reduce_agg (value, 's', (a, b) -> concat (a, b, 's'), (a, b) -> concat (a, b, 's')) FROM ( VALUES (1, '2'), (1, '3'), (1, '4'), (2, '20'), (2, '30'), (2, '40') ) AS t (id, value) GROUP BY id", "value group_concat只有与group by语句同时使用才能产生效果 所以使用 GROUP_CONCAT（）函数必须对源数据进行分组，否则所有数据会被合并成一行 Learn how to use the CONCAT function in Apache Presto for string manipulation and data processing. It supports being used with an ORDER BY clause, which uses the expected syntax, unlike LISTAGG(), which uses the WITHIN GROUP syntax. May 26, 2025 · 在Presto中如何实现类似SQL的GROUP_CONCAT函数按分组拼接字符串？ Presto本身并没有直接提供名为`GROUP_CONCAT`的函数，但可以通过`array_agg`与`array_join`函数组合实现类似功能。例如，若需按某一列分组并将另一列的值拼接成字符串，可先用`array_agg`收集值为数组，再用`array_join`将数组转换为以特定分隔符 In this video, we’ll explore how to leverage Presto's equivalent of MySQL's GROUP_CONCAT function to efficiently aggregate and concatenate string values from Alternative syntax of Group_concat in MySQL in Hive and PRESTO, Programmer Sought, the best programmer technical posts sharing site. Returns true if all the elements match the predicate (a special case is when the array is empty); false if one or more elements don’t match; NULL if the predicate function returns NULL for one or more elements and true for all other elements. Except for How to concatenate arrays grouped by another column in Presto? Asked 7 years, 1 month ago Modified 2 years, 3 months ago Viewed 19k times bit_length (string) -> boolean() Returns the count of bits for the given string. MySQL group_concat函数的Presto等价物 在MySQL中，group_concat函数允许将同一列中的多个值组合成一个字符串，这在许多数据分析场景中非常有用。 但是，如果您正在使用Presto，则需要找到类似的函数来执行相同的操作。 May 31, 2019 · Athena is based on Presto. Dec 4, 2024 · I'm new to Presto and looking to get the same functionality as the group_concat function in MySQL. String functions and operators String operators The || operator performs concatenation. Typically, more than 99. Due to connection timeout or some problem in worker nodes, this network data transfer may fail occasionally (PAGE_TRANSPORT_TIMEOUT, WORKER_RESTARTED). 1 什么是Presto Presto是一个开源的分布式SQL查询引擎，由Facebook开发。它的设计目标是在处理大规模数据时提供快速、灵活和可扩展的查询能力。Presto支持标准的SQL语法，并且能够直接查询多种数据源，如Hadoop、Hive、MySQL、PostgreSQL等 SQL Presto等效的CONCAT_WS函数 在本文中，我们将介绍 SQL Presto中的CONCAT_WS函数以及它的用法和等效的替代方法。 阅读更多： SQL 教程 什么是CONCAT_WS函数？ CONCAT_WS是一个SQL函数，用于将多个字符串连接起来，其中WS代表With Separator。该函数接受一个分隔符作为参数，并将多个字符串使用该分隔符连接成 Jul 20, 2020 · Right now I have maxprice and minprice as two separate columns, but I want to combine them into one column "price range" which will have minprice and maxprice separated by a " - " string, so it would look something like this: Jul 21, 2021 · I presto sql, I can do ARRAY_AGG(text ORDER BY time), how can I do it in MySQL? I found CONCAT_WS(',', COLLECT_LIST(text)) can do partial work, but not sure how to order by time in a quick way. Jun 30, 2020 · Correct syntax for presto CONCAT(CAST(WEEK(CAST(processing_payment_date as DATE) + INTERVAL '1' DAY) as VARCHAR), ' - WEEK') as week. I am wondering could I do it directly in Presto query? Apr 24, 2017 · Aggregate strings in group by and ordered in Hive and Presto Asked 8 years, 6 months ago Modified 6 years, 3 months ago Viewed 12k times Aug 26, 2023 · 文章浏览阅读1. The worst feeling when you overlook the simple solution. String functions 以下是一个示例查询： group_concat presto写法 “group_concat”是一种在Presto数据库中使用的函数，用来在查询结果中将每个分组的多个值合并为一个字符串。 这个函数非常有用，特别是当我们需要将多个值串联起来，以便更清晰地展示数据。 Nov 12, 2024 · 文章浏览阅读2. For engine version 3, Athena has introduced a continuous integration approach to open source software management that improves concurrency with the Trino and Presto projects so that you get faster access to community improvements, integrated and tuned within the Athena engine. 2w次。本文详细介绍了Presto和Hive在处理字符串时的函数用法，包括substr/split/position/concat等，并举例说明了各自 GROUP BY array_items; In the last SELECT statement, instead of using sum() and UNNEST, you can use reduce() to decrease processing time and data transfer, as in the following example. Result string_concat ---------------- tutorialspoint The above output is concatenation of the given strings. and wanted result as: Tried : concat_ws(':', nrarf, chDl, Indicator, carrier, cellTech, Nov 1, 2024 · Learn how to efficiently use the GROUP BY clause with GROUP_CONCAT to concatenate strings in MySQL, along with practical solutions for handling NULLs, sorting, and customizing separators. To adjust text string values, you may find these common functions useful. Discover examples and best practices. I'm new to Presto and looking to get the same functionality as the group_concat function in MySQL. So you could, of course, use it in Presto installations, but also in some other » read more Nov 16, 2014 · The official home of the Presto distributed SQL query engine for big data - Implement string aggregation function · Issue #1976 · prestodb/presto May 23, 2017 · 我是Presto的新手，希望获得与MySQL中的group_concat函数相同的功能。下面两个是等价的吗？如果没有，对如何在Presto中重新创建group_concat功能有什么建议吗？MySQL：select a, group_concat(b separator ',')from tablegroup b 23 SELECT id, GROUP_CONCAT(name SEPARATOR ' ') FROM table GROUP BY id; :- In MySQL, you can get the concatenated values of expression combinations . This release of Athena engine version 3 supports all the features of previous engine versions. See Presto Sep 16, 2025 · 文章浏览阅读1. map_agg(key, value) → map<K,V> Returns a map created from the input key / value pairs. We would like to show you a description here but the site won’t allow us. This document GROUP_CONCAT函数是Presto中一个强大的工具，可以帮助我们轻松地将一组值连接成一个字符串。 通过理解其基本语法、如何使用自定义分隔符、排序结果、处理NULL值以及限制返回结果的长度，我们可以更有效地利用GROUP_CONCAT函数进行数据处理和分析。 Array Functions and Operators Subscript Operator: [] The [] operator is used to access an element of an array and is indexed starting from one: Nov 20, 2019 · Presto SQL - distinct in selective group by Asked 5 years, 3 months ago Modified 5 years, 3 months ago Viewed 15k times LISTAGG is the new SQL standard version of GROUP_CONCAT or STRING_AGG. tb_student group by city; About Presto SQL ¶ Presto is a distributed SQL query engine designed to efficiently query large amounts of data using distributed queries. However, you can use identical expression, e. le12ijppxuzcyv7uig5wkbctmr18zlty7mihrebyh8lh