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    SQL

    ลำดับตอนที่ #3 : SQL I - Processing the Results

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      4 ม.ค. 62

    Ordering Rows


     

    ORDER BY

    To put rows in order, you can use ORDER BY in SQL. You can also choose a specific column to use order the rows by, as shown in the example below. You must also specify how the rows should be ordered at the end.


    Ascending & Descending Order

    ORDER BY requires a method for ordering, either "ascending" or "descending". Ascending will put the smallest values first in the order. Descending will put the largest values first. In SQL code, ASC is used for "ascending" and DESC for "descending".


    By putting ORDER BY at the end of an SQL statement, the results can be put neatly in order, as shown in the example below.


    Since ORDER BY is used at the end of an SQL statement, it can be used in combination with a WHERE clause, as shown below.



    Getting Only the Needed Rows

     


    LIMIT

    To set a specific "maximum number of results", you can use LIMIT. See how it works in the example below.


    Just like ORDER BY, LIMIT comes at the end of an SQL statement. So, you can use it to restrict the number of results.


    Furthermore, LIMIT can be used in combination with a WHERE clause, just as with ORDER BY.



    Lesson Review

     

     

    Applying What You've Learned

    Supplementary Combining ORDER BY with LIMIT

    Both ORDER BY and LIMIT come at the end of an SQL statement, but it is possible to use them together in the same statement. However, when using them in combination, LIMIT must come at the very end. Below is an example demonstrating how to get the only the 5 highest prices.


     



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