MySQL Bugs: #23264: MyODBC driver returns 'x' instead of empty string when IF applies on TEXT field

Bug #23264	MyODBC driver returns 'x' instead of empty string when IF applies on TEXT field
Submitted:	13 Oct 2006 15:35	Modified:	17 Dec 2009 5:25
Reporter:	Bogdan Degtyariov	Email Updates:
Status:	Closed	Impact on me:	None
Category:	Connector / ODBC	Severity:	S2 (Serious)
Version:	3.51	OS:	Any
Assigned to:	Bogdan Degtyariov	CPU Architecture:	Any
Tags:	IIS

Description:
mysql> CREATE TEMPORARY TABLE test_if_text_x_bug(mytext TEXT NULL, myvarchar VARCHAR(255) NULL)

Query OK, 0 rows affected (0.00 sec)

mysql> INSERT INTO test_if_text_x_bug(mytext,myvarchar) VALUES('abc', 'def')

mysql> SELECT IF (0, mytext, '') AS expr1, IF (0, mytext, 'abc') AS expr2, IF (0, myvarchar, '') AS expr3 FROM test_if_text_x_bug
-> ;
+-------+-------+-------+
| expr1 | expr2 | expr3 |
+-------+-------+-------+
|       | abc   |       |
+-------+-------+-------+

whereas MyODBC returns 'x' for expr1

How to repeat:
Run the .asp script from the file below

test case

Attachment: mysql_x_bug.asp (application/octet-stream, text), 2.22 KiB.

SQLGetData() returns SQL_NO_DATA_FOUND status when result is empty string. However, it should fill the data buffer with \0 character in any case to prevent using old result that is already in the buffer

I get the same problem. Did you find a solution?

Bogdan, reopening on the basis of Matthew's remark in Bug#30496.

SQLGetData() should NOT touch the buffer if returning SQL_NO_DATA.

Verified with the driver version 3.51.27. No bug was detected using the old test case mysql_x_bug.asp (http://bugs.mysql.com/file.php?id=4614). The driver returned correct results even after changing connection string as indicated in the duplicated bug#30946:

Driver={MySQL ODBC 3.51 Driver};Server=***;Port=3306;Database=enrol;User=*
***;Password=***;Option=3;"

I am closing this bug report once again. If anybody still have similar problems, please attach your test case.
Thanks.

Bug#42325 was marked as duplicate of this report.