Detailed introduction to group_concat()

The example in this article describes the usage of the mysql group_concat() function. Share it with everyone for your reference, the details are as follows: group_concat(), the manual explains: This function returns a string result with a non-NULL value from the connection of a group. Relatively abstract and difficult to understand. To understand it in a simple way, it is actually like this: group_concat() will calculate which rows belong to the same group and display the columns belonging to the same group. Which columns to return are determined by the function parameters (field names). There must be a standard for grouping, which is to group based on the column specified by group by. The group_concat function should execute the group by statement internally, this is my guess. 1. Test statement: SELECT group_concat(town) FROM `players` group by town results to find which values ​​in town are the same. If they are equal, list them all, separated by commas, as follows: group_conc

1. Summary of how to use the group_concat() function in mysql

Introduction: The example in this article describes the usage of mysql group_concat() function. Share it with everyone for your reference, the details are as follows: group_concat(), the manual explains: This function returns a string result with a non-NULL value from the connection of a group. Relatively abstract and difficult to understand. To understand it in a simple way, it is actually like this: group_concat() will calculate which rows belong to the same group and display the columns belonging to the same group. To return

2. How to use Mysql's GROUP_CONCAT() function_PHP tutorial

Introduction: Mysql's GROUP_CONCAT () function usage. Syntax: GROUP_CONCAT([DISTINCT]expr[,expr...][ORDERBY{unsigned_integer|col_name|expr}[ASC|DESC][,col_name...]][SEPARATORstr_val]) Let’s demonstrate this function. First create one Learn

3. mysql group_concat() function usage summary_MySQL

##Introduction: This article mainly introduces Mysql group_concat() function usage, combined with the more detailed function, usage and related precautions of the group_concat() function in the form of an example, friends in need can refer to

4. How to use Mysql's GROUP_CONCAT() function

Introduction: How to use Mysql's GROUP_CONCAT() function. Syntax: GROUP_CONCAT([DISTINCT]expr[,expr...][ORDERBY{unsigned_integer|col_name|expr}[ASC|DESC][,col_name...]][SEPARATORstr_val]) Let’s demonstrate this function. First create one Learn

5. Mysql function GROUP_CONCAT

Introduction: GROUP_CONCAT() is a function provided by the MySQL database, usually Used together with GROUP BY, please refer to MySQL official documentation for details: http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat. Syntax: GROUP_CONCAT([DISTINCT]?expr?[,expr ...]?[ORDER?BY?{unsigne

6. mysql uses group_concat() to merge multiple rows Data to one row

#Introduction: Assume that two tables a, b, b are associated with table a through the field id, and table a and table b have a one-to-many relationship. Assume that there is a field name in table b. Now we need to query the records in table a and obtain the name information stored in table b. According to the conventional query, how many records are in table b will be displayed, and how many rows will be displayed. If necessary, only display To record the number of rows in table a, you need to query the name field to

7. MySQL function: group_concat() function

Introduction: GROUP_CONCAT(expr) This function combines non-empty column values ​​according to grouping conditions and finally returns. If there are null values, it returns empty. The complete syntax is as follows: GROUP_CONCAT([

8. The difference between concat and concat_ws() and group_concat(), repeat() string function_MySQL

Introduction: concat and concat_ws() Differences between group_concat() and repeat() string functions

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