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MariaDB server is a community developed fork of MySQL server. Started by core members of the original MySQL team, MariaDB actively works with outside developers to deliver the most featureful, stable, and sanely licensed open SQL server in the industry.
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RESULT CONSISTED OF MORE THAN ONE ROW MySQL converts incorrect DATEs and DATETIMEs to '0000-00-00' on insertion by default. This means that this sequence is possible: CREATE TABLE t1(date_notnull DATE NOT NULL); INSERT INTO t1 values (NULL); SELECT * FROM t1; 0000-00-00 At the same time, ODBC drivers do not (or at least did not in the 90's) understand the DATE and DATETIME value '0000-00-00'. Thus, to be able to query for the value 0000-00-00 it was decided in MySQL 4.x (or maybe even before that) that for the special case of DATE/DATETIME NOT NULL columns, the query "SELECT ... WHERE date_notnull IS NULL" should return rows with date_notnull == '0000-00-00'. This is documented misbehavior that we do not want to change. The hack used to make MySQL return these rows is to convert "date_notnull IS NULL" to "date_notnull = 0". This is, however, only done if the table date_notnull belongs to is not an inner table of an outer join. The rationale for this seems to be that if there is no join match for the row in the outer table, null-complemented rows would otherwise not be returned because the null-complemented DATE value is actually NULL. On the other hand, this means that the "return rows with 0000-00-00 when the query asks for IS NULL"-hack is not in effect for outer joins. In this bug, we have a LEFT JOIN that does not misbehave like the documentation says it should. The fix is to rewrite "date_notnull IS NULL" to "date_notnull IS NULL OR date_notnull = 0" if dealing with an OUTER JOIN, otherwise "date_notnull IS NULL" to "date_notnull = 0" as was done before. Note: The bug was originally reported as different result on first and second execution of SP. The reason was that during first execution the query was correctly rewritten to an inner join due to a null-rejecting predicate. On second execution the "IS NULL" -> "= 0" rewrite was done because there was no outer join. The real problem, though, was incorrect date/datetime IS NULL handling for OUTER JOINs. mysql-test/r/type_datetime.result: Add test for BUG#12561818 mysql-test/t/type_datetime.test: Add test for BUG#12561818 sql/sql_select.cc: Special handling of NULL for DATE/DATETIME NOT NULL columns: In the case of outer join, "date_notnull IS NULL" is now rewritten to "date_notnull IS NULL OR date_notnull = 0" |
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client | ||
cmake | ||
cmd-line-utils | ||
dbug | ||
Docs | ||
extra | ||
include | ||
libmysql | ||
libmysqld | ||
libservices | ||
man | ||
mysql-test | ||
mysys | ||
packaging/WiX | ||
plugin | ||
regex | ||
scripts | ||
sql | ||
sql-bench | ||
sql-common | ||
storage | ||
strings | ||
support-files | ||
tests | ||
unittest | ||
vio | ||
win | ||
zlib | ||
.bzrignore | ||
BUILD-CMAKE | ||
CMakeLists.txt | ||
config.h.cmake | ||
configure.cmake | ||
COPYING | ||
INSTALL-SOURCE | ||
INSTALL-WIN-SOURCE | ||
README | ||
VERSION |
MySQL Server 5.5 This is a release of MySQL, a dual-license SQL database server. For the avoidance of doubt, this particular copy of the software is released under the version 2 of the GNU General Public License. MySQL is brought to you by Oracle. Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved. License information can be found in the COPYING file. MySQL FOSS License Exception We want free and open source software applications under certain licenses to be able to use specified GPL-licensed MySQL client libraries despite the fact that not all such FOSS licenses are compatible with version 2 of the GNU General Public License. Therefore there are special exceptions to the terms and conditions of the GPLv2 as applied to these client libraries, which are identified and described in more detail in the FOSS License Exception at <http://www.mysql.com/about/legal/licensing/foss-exception.html>. This distribution may include materials developed by third parties. For license and attribution notices for these materials, please refer to the documentation that accompanies this distribution (see the "Licenses for Third-Party Components" appendix) or view the online documentation at <http://dev.mysql.com/doc/>. GPLv2 Disclaimer For the avoidance of doubt, except that if any license choice other than GPL or LGPL is available it will apply instead, Oracle elects to use only the General Public License version 2 (GPLv2) at this time for any software where a choice of GPL license versions is made available with the language indicating that GPLv2 or any later version may be used, or where a choice of which version of the GPL is applied is otherwise unspecified. For further information about MySQL or additional documentation, see: - The latest information about MySQL: http://www.mysql.com - The current MySQL documentation: http://dev.mysql.com/doc Some Reference Manual sections of special interest: - If you are migrating from an older version of MySQL, please read the "Upgrading from..." section. - To see what MySQL can do, take a look at the features section. - For installation instructions, see the Installing and Upgrading chapter. - For the new features/bugfix history, see the MySQL Change History appendix. You can browse the MySQL Reference Manual online or download it in any of several formats at the URL given earlier in this file. Source distributions include a local copy of the manual in the Docs directory.