MySQL tutorial: use variables to generate row numbers for each row
Mysql row number - we can implement it through variables. mysql> set @id = 0;mysql> select @id := @id + 1 as id ......
MySQL tutorial: column to row use group by and group_concat function
Mysql column to row - use group by the data set, and then associate the column data through the group_concat function....
MySQL tutorial: mysql inner, left, right, full join explained
Mysq joins two table query, roughly divided into inner join, full join (outer join), right join, and left join....
MySQL tutorial: mysql round() function
MySQL ROUND() is a mathematical function that rounds Numbers to a specified number of decimal places....