What are the rules for sorting multiple fields in MySQL?

In MySQL, the rule for sorting multiple fields is to sort them in the specified order. When multiple fields are involved in sorting, MySQL first sorts by the first field, and if there are equal values, it sorts by the second field, and so on.

For example, there is a table with three fields (Field A, Field B, Field C) that needs to be sorted first by Field A, then by Field B if Field A values are the same, and finally by Field C if Field B values are also the same.

Multiple field sorting can be achieved by using the ORDER BY clause. An example query is shown below:

Retrieve all data from the table sorted by columns A, B, and C.

This will be sorted according to Field A, with Field B as a secondary sorting criterion in case of identical values in Field A, and Field C will be used as the final sorting criterion if Field B is also the same.