How to merge rows in mysql

Mysql method of merging rows: use the function [GROUP_CONCAT()], the code is [SELECT am.activeId,GROUP_CONCAT(m.modelName SEPARATOR ',') modelName].

[Related learning recommendations: mysql learning]

Mysql merge row method:

A field may correspond to multiple pieces of data. Use mysql to merge multiple rows of data into one row of data.

For example: an activity id (activeId) corresponds to multiple module names (modelName). According to the general The sql statement:

1 SELECT am.activeId,m.modelName 
2 FROM activemodel am 
3 JOIN  model m 
4 ON am.modelId = m.modelId 
5 ORDER BY am.activeId

The query list is shown in Figure 1:

##Figure 1

After modification sql statement, as shown in Figure 2 after query:

1 SELECT am.activeId,GROUP_CONCAT(m.modelName SEPARATOR ',') modelName
2 FROM activemodel am 
3 JOIN model m 
4 ON am.modelId=m.modelId
5 WHERE m.valid=1
6 GROUP BY am.activeId

Note:

##1.

GROUP_CONCAT()

The value in is the field name of the data you want to merge ;The SEPARATOR function is used to separate the data to be merged;

' '

is which symbol you want to use to separate; 2. The GROUP BY statement must be used for group management, otherwise all data will be merged into one record, as shown in Figure 3

Figure 2

image 3

The above is the detailed content of How to merge rows in mysql. For more information, please follow other related articles on the PHP Chinese website!