| Bug #33594 | DatabaseMetaData misbehaviour when server side cursors are enabled | ||
|---|---|---|---|
| Submitted: | 31 Dec 2007 8:43 | Modified: | 25 Feb 2008 12:12 |
| Reporter: | Andrea Aime | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | Connector / J | Severity: | S2 (Serious) |
| Version: | 5.1.5 | OS: | Windows |
| Assigned to: | CPU Architecture: | Any | |
| Tags: | DataBaseMetaData useCursorFetch | ||
[3 Jan 2008 11:05]
Tonci Grgin
Test case
Attachment: TestBug33594.java (text/java), 3.55 KiB.
[3 Jan 2008 11:13]
Tonci Grgin
Hi Andrea and thanks for your report. This is more of an issue of useInformationSchema true/false as when useInformationSchema is true all works as expected (please see attached test case). As you are probably using MySQL server > 5.0.7 useInformationSchema=True is a legitimate workaround (and not too complicated) so please lower the Severity to S3 or S2 at most. Verified using latest c/J 5.1 sources. Output of attached test case: useInformationSchema = true .Loading JDBC driver 'com.mysql.jdbc.Driver' Done. Done. java.vm.version : 1.5.0_12-b04 java.vm.vendor : Sun Microsystems Inc. java.runtime.version : 1.5.0_12-b04 os.name : Windows XP os.version : null sun.management.compiler : HotSpot Client Compiler Connected to 5.0.54-max-nt-log Time: 0,375 OK (1 test) ---------------- useInformationSchema = false .Loading JDBC driver 'com.mysql.jdbc.Driver' Done. Done. java.vm.version : 1.5.0_12-b04 java.vm.vendor : Sun Microsystems Inc. java.runtime.version : 1.5.0_12-b04 os.name : Windows XP os.version : null sun.management.compiler : HotSpot Client Compiler Connected to 5.0.54-max-nt-log F Time: 0,422 There was 1 failure: 1) testBug33594(testsuite.simple.TestBug33594)junit.framework.ComparisonFailure: expected:<fid> but was:<varchar(255)> at testsuite.simple.TestBug33594.testBug33594(TestBug33594.java:48) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at testsuite.simple.TestBug33594.main(TestBug33594.java:68) FAILURES!!! Tests run: 1, Failures: 1, Errors: 0
[3 Jan 2008 11:16]
Andrea Aime
Hum, does appending InformationSchema=True to the jdbc url causes any problem with older versions of mysql? The code I'm writing is a library (GeoTools) not an application with a specific target db, so whatever I do must work across the board with all versions of mysql.
[3 Jan 2008 11:20]
Tonci Grgin
Andrea, alas yes it does... See my test case and previous comment (VersionMeetsMinimum). Changing triage to "Partial workaround". Thanks for lowering severity.
[3 Jan 2008 11:40]
Andrea Aime
I don't understand that versionMeetsMinimum comment... that is a method defined somewhere in one of your test base classes. So you say I should find that code, check the version, and apply the extra param only if version if >= 5.0.7?
[3 Jan 2008 11:42]
Tonci Grgin
Andrea, true. Please get c/J sources so you can look it up.
[3 Jan 2008 15:30]
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/40511
[4 Jan 2008 22:06]
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/40588
[25 Feb 2008 12:12]
MC Brown
A note has been added to the 5.1.6 changelog: Using server side cursors and cursor fetch, the table metadata information would return the data type name instead of the column name.
Description: When using cursor fetch the table metadata returns the data type name in place of the column name. How to repeat: Given the following table: mysql> describe road; +-------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+--------------+------+-----+---------+-------+ | fid | varchar(255) | NO | PRI | | | | id | int(11) | YES | | NULL | | | geom | linestring | YES | | NULL | | | name | varchar(255) | YES | | NULL | | +-------+--------------+------+-----+---------+-------+ And a connection using the extra parameters "?useCursorFetch=true&defaultFetchSize=100" we find that database metadata extraction misbehaves in that the column type is returned when the column name is requested, that is, the following code: DatabaseMetaData dbMetaData = conn.getMetaData(); ResultSet tableInfo = dbMetaData.getColumns(null, null, "road", "%"); tableInfo.next(); String colName = tableInfo.getString("NAME_COLUMN"); returns "varchar(255)" instead of "fid". Removing the above parameters from the connection string restores normal behaviour.