| Bug #11589 | prepared statements - strange output, float/double/real with zerofill | ||
|---|---|---|---|
| Submitted: | 27 Jun 2005 12:29 | Modified: | 25 Oct 2007 0:02 |
| Reporter: | Matthias Leich | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | MySQL Server: Prepared statements | Severity: | S3 (Non-critical) |
| Version: | 4.1 | OS: | Any |
| Assigned to: | Magnus Blåudd | CPU Architecture: | Any |
[27 Jun 2005 12:30]
Matthias Leich
Testcase
Attachment: ml021.test (application/test, text), 364 bytes.
[8 Jul 2005 8:36]
Matthias Leich
The problem with the differing output does also appear with non
zerofill float/double/real values.
Without --ps-protocol :
CREATE TABLE t1 (f1 DOUBLE);
INSERT INTO t1 SET f1 =
-1.79769313486231e+308;;
SELECT f1 AS f1_direct FROM t1;
f1_direct
-1.79769313486231e+308
SELECT f1 AS f1_eval FROM t1;
f1_eval (Executed via eval)
-1.79769313486231e+308
PREPARE my_sel FROM 'SELECT f1 AS f1_prepared FROM t1';
EXECUTE my_sel;
f1_prepared
-1.79769313486231e+308
All SELECT variants give the same result
-1.79769313486231e+308 (= mantissa 15 digits).
With --ps-protocol :
...
SELECT f1 AS f1_direct FROM t1;
f1_direct
-1.7976931348623e+308 ( = mantissa 14 digits)
###
All other SELECT variants give the same result
-1.79769313486231e+308.
When I shorten the mantissa to 14 digits
(INSERT of -1.7976931348623e+308)
the problem disappears.
The file ml033.test contains this testcase.
[8 Jul 2005 8:39]
Matthias Leich
testcase
Attachment: ml033.test (application/test, text), 486 bytes.
[21 Feb 2006 13:56]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/2972
[21 Feb 2006 17:51]
Magnus Blåudd
The patch will correct "zerofill" problem. I.e first part of this bug report.
[21 Jul 2006 10:05]
Magnus Blåudd
Splitting this bug in two, new bug#21205 created for the second problem. The patch already provided is ready to go into 5.0 when approved.
[18 Oct 2007 21:36]
Bugs System
Pushed into 5.1.23-beta
[18 Oct 2007 21:37]
Bugs System
Pushed into 5.0.52
[25 Oct 2007 0:02]
Paul DuBois
Noted in 5.0.52, 5.1.23 changelogs. Values of types REAL ZEROFILL, DOUBLE ZEROFILL, FLOAT ZEROFILL, were not zero-filled when converted to a character representation in the C prepared statement API.
Description: The option "--ps-protocol" causes strange output when selecting on columns of the data type real/double/float zerofill. Example: CREATE TABLE t1 (f1 real zerofill,f2 double zerofill,f3 float zerofill); INSERT INTO t1 VALUES ( 0.314152e+1, 0.314152e+1, 0.314152e+1); PREPARE stmt1 FROM 'select f1, f2, f3 FROM t1'; <without --ps-protocol> select f1, f2, f3 FROM t1; f1 f2 f3 0000000000000003.14152 0000000000000003.14152 000003.14152 select f1, f2, f3 FROM t1; <-- executed via eval $stmt f1 f2 f3 0000000000000003.14152 0000000000000003.14152 000003.14152 EXECUTE stmt1; f1 f2 f3 0000000000000003.14152 0000000000000003.14152 000003.14152 <with --ps-protocol> select f1, f2, f3 FROM t1; f1 f2 f3 3.14152 3.14152 3.14152 ################# select f1, f2, f3 FROM t1; <-- executed via eval $stmt f1 f2 f3 0000000000000003.14152 0000000000000003.14152 000003.14152 EXECUTE stmt1; f1 f2 f3 0000000000000003.14152 0000000000000003.14152 000003.14152 The option "--ps-protocol" should cause the usage of prepared statements as much as possible. Therefore I expect to get an output similar to the explicit use (Prepare,Execute) of prepared statements. Unfortunately that does not happen. I guess - the printed values are logically correct, but "--ps-protocol" uses the "wrong" physical formatting - this bug is not important for customers . But it harms the development of testscripts, because it is expected, that testprotocols are nearly independend of the usage of the "--ps-protocol" option. My environment: - Intel PC with Linux(SuSE 9.3) - MySQL compiled from source Version 4.1 ChangeSet@1.2306, 2005-06-21 Version 5.0 ChangeSet@1.1989.2.1, 2005-06-23 How to repeat: Please use the attached testcase ml021.test. copy it to mysql-test/t touch r/ml021.result # Produce a dummy file with # expected results ./mysql-test-run ml021 mv r/ml021.reject r/ml021.result ./mysql-test-run --ps-protocol ml021 compare r/ml021.reject and r/ml021.result