A Little Noise

Capital. Just capital.

Written by

snoyes

in

Culled from the Certification Study Guide:

mysql> SELECT * FROM test;
+----------------+
| data           |
+----------------+
| This is a test |
+----------------+
1 row in set (0.00 sec)

mysql> SELECT UPPER(data) FROM test;
+----------------+
| UPPER(data)    |
+----------------+
| This is a test |
+----------------+
1 row in set (0.03 sec)

How’s that work?

 CREATE TABLE `test` (
   `data` varbinary(255) default NULL
 );

Binary strings are just a list of bytes. They aren’t characters anymore, so there is no upper or lower case. Remember that when choosing between char/varchar/text and binary/varbinary/blob.

Comments

3 responses to “Capital. Just capital.”

  1. Jason Avatar
    Jason

    I’d call this a bug. The Upper() function is defined as taking a string argument and returning a string. It mentions nothing about accepting binary as an argument.
    If you pass it something that is not a string to the upper() function it should either:
    1) Return an error
    OR (better)
    2) Convert the argument to a string and perform the desired function.

    The fact that this is in a study guide for certification is bad.

  2. snoyes Avatar
    snoyes

    binary is a string. It’s just not a string of characters; it’s a string of bytes.

  3. Matt Avatar
    Matt

    I agree with Jason. This is the sort of poor unexpected behavior you would get from weakly typed systems. Force an error to make the user understand the expected behavior, eliminating bugs.

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