---+ | id| group_concat(name order by name desc) | +---+---+ |1 | 20,20,10 | |2 | 20| |3 | 500,200| +---+---+ 3 rows in set (0.00 sec) 6.使用group_concat_max_len系统变量,你可以设置允许的最大长度。 程序中进行这项操作的语法如下,其中 val 是一个无符号整数: SET...
SQL行转列、列转行 编程算法sqlhttps网络安全 这个主题还是比较常见的,行转列主要适用于对数据作聚合统计,如统计某类目的商品在某个时间区间的销售情况。列转行问题同样也很常见。 全栈程序员站长 2022/07/21 1.7K0 SQL中进行转列的几种方式 sql编程算法 在很多笔试的程序员中会有很多写SQL的情况,其中很多时候会...
在SQLyog中执行 SET GLOBAL group_concat_max_len = 10 后,重新打开SQLyog,设置就会生效。
'VARCHAR' is not a recognized built-in function name. 'WHEN MATCHED' cannot appear more than once in a 'UPDATE' clause of a MERGE statement. "EXECUTE AT" with Dynamic Linked Server Name "explicit value must be specified for identity column in table" error in SQL 2000 "FROM clause have ...
如何用一个SQL查询出一个班级各个学科第N名是谁? 首先贴出建表语句,方便大家本地测试: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 -- 建表语句 CREATETABLEscore ( idINTNOTNULLauto_increment, `name`VARCHAR(20)NOTNULLDEFAULT''COMMENT'姓名', ...
Oracle Database provides a wide range of powerful SQL functions to manipulate and aggregate data. One such commonly used function is GROUP_CONCAT,which allows us to combine rows into a single string. In this article, we will explore the features, syntax, and usage of Oracle GROUP_CONCAT funct...
sql GROUP_CONCAT([DISTINCT] expression [ORDER BY expression ASC|DESC] [SEPARATOR 'separator']) Powered By In this syntax, `expression` represents the column or value to be concatenated, and `SEPARATOR` defines the delimiter between concatenated values. The default separator is a comma. Example...
(id,GROUP_CONCAT(id))ASCourseIDs,JSON_OBJECTAGG(id,name)ASCoursesFROMcourseGROUPBYdepartment_id\G ERROR1055(42000): Expression #1ofSELECTlistisnotinGROUPBYclauseandcontainsnonaggregatedcolumn'university.course.id'whichisnotfunctionally dependentoncolumnsinGROUPBYclause; thisisincompatiblewithsql_mode=only_...
ORDER BY GROUP_CONCAT(DISTINCT cate_id) ASC; -- Orders the results by the concatenated category IDs in ascending order Explanation: This SQL query retrieves data from the book_mast table. It concatenates distinct category IDs for each publisher and orders the results by the concatenated category...
The problem here is that the delimiter part of StringAgg is included in the expressions, which probably makes it complex. From the syntax defined by Postgresql, the expression is explicitly separated from the delimiter: string_agg(expression, delimiter) string_agg comment:7 by Mariusz ...