Database SQL language 03 sorting and paging

Sorting and paging

 grammar  : ORDER BY
ORDER BY  Statement to sort the result set according to the specified column .
ORDER BY  Statement defaults to ASC Sort records in ascending order .
 If you want to sort records in descending order , have access to  DESC  keyword .

 grammar  : SELECT * FROM table LIMIT [offset,] rows | rows OFFSET offset
 benefits  : ( User experience , Network transmission , Query pressure )

 deduction :
 first page  : limit 0,5
 The second page  : limit 5,5
 The third page  : limit 10,5
......
 The first N page  : limit (pageNo-1)*pageSzie,pageSzie
[pageNo: Page number ,pageSize: Number of single page displays ]

The Department is required to be 30 Information about the third highest paid person :

Our key is to get empno = 7844 sal =1500 This employee :

2,1 Indicates the third , Take the back 1 individual , among 2 Indicates the third , from 0 Start the first one :