MySQL group query description

1. Grammar

See the code block below for specific statement templates. It should be noted that "[]" enclosed in Chinese brackets indicates non-essential code segments. The number sequence number behind indicates the execution order of its SQL statement.

### 语法模板

SELECT 分组函数, 分组后的字段                  ### 5
FROM 数据表名                                 ### 1
【 WHERE 筛选条件 】                          ### 2
GROUP BY 分组后的字段                         ### 3
【 HAVING 分组后的字段筛选 】                  ### 4
【 ORDER BY 排序列表 】                       ### 6

Second, the difference between WHERE and HAVING

Keyword	effect	Filtered table	position
WHERE	Filter before grouping	Original table	Before GROUP BY
HAVING	Filter after grouping	Grouped result set	After GROUP BY