In MySQL, you can get the concatenated values of expression combinations. To eliminate duplicate values, use the DISTINCT clause. To sort values in the result, use the ORDER BY clause. To sort in reverse order, add the DESC (descending) keyword to the name of the column you are sorting ...
这样获取到数据之后使用AuthorityUtils.commaSeparatedStringToAuthorityList...list集合,数据库中字段信息如下 如图所示,用户role字段对应用户角色信息,但是用户角色可能会添加也可能会删除某个角色,当然查出来利用java语言拼接字符串是肯定没问题的,通过查找资料我决定使用...MySQL的concat函数,及service层将要添加的角色字符...
In MySQL, you can easily concatenate strings by specifying them within single or double quotes and separating them with spaces. This automatically results in a single concatenated string that appends all the selected strings, separated by spaces. Consider a simple example where we want to concatenate...
Summary: in this tutorial, you will learn how to use the MySQL GROUP_CONCAT function to concatenate strings from a group of values with various options. Introduction to MySQL GROUP_CONCAT function The GROUP_CONCAT function concatenates strings from a group into one string with various options. ...
mysql group_concat group_concat,返回group中非null值连接起来的字符串。 默认分割符是逗号,使用separator指定分隔符。 用distinct过滤重复值。 用order by排序,默认是升序,asc明确升序;desc降序 GROUP_CONCAT(expr) This function returns a string result with the concatenated non-NULL...
4.Can the output of MySQL GROUP_CONCAT() be customized? Yes, the function allows customization: Custom Separators: Besides the default comma, you can define any separator character or string. Ordering: Values can be ordered in ascending or descending order before concatenation. ...
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', subVARCHAR(20)NOTNULLDEFAULT''COMMENT'学科', ...
SEPARATOR: This clause sets the string literal inserted between the group’s values upon the concatenation process. By default, MySQL uses a comma (,) to separate the values. NOTE:The string result generated by MySQL GROUP_CONCAT() function is limited to a length the value set in the group...
MySQL The `GROUP_CONCAT()` function in MySQL concatenates values from multiple rows into a single string, grouped by a specified column. This function is particularly useful for creating comma-separated lists from grouped results. Usage `GROUP_CONCAT()` is used when you need to aggregate string...
Mysql and group_concat() maximum length Code Example, //if you can want increase the group_contat max length SET SESSION group_concat_max_len = 1000000; All Results Not Returned by GROUP_CONCAT in MySQL Question: To obtain comma-separated results (,), I utilized GROUP_CONCAT. However, upo...