SQL statement execution Shun seek

SQL statements are executed in a certain order. Understanding this order is a great help in using and learning SQL.

1.from

First select a table, or source, to form a result set.

2.where

Then use where to filter the result set. Filter out the information needed to form a new result set.

3.group by

Group the new result set.

4.having

Filter out the groups you want.

5.select

Select the column.

6.order by

When all the conditions are done. The last sort.

This is the order in which the SQL statements are executed.