/ Check-in [e22e3ab5]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Added information on MySQL 4.0.16 to the NULL-handling survey. (CVS 1117)
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1:e22e3ab53a841b26984240760b0438efc83661d7
User & Date: drh 2003-11-08 12:07:01
Context
2003-11-11
23:30
Fix a typo in a #define that was commented out. No impact to working code. Ticket #476. (CVS 1119) check-in: 21c2f96e user: drh tags: trunk
2003-11-08
12:07
Added information on MySQL 4.0.16 to the NULL-handling survey. (CVS 1117) check-in: e22e3ab5 user: drh tags: trunk
2003-11-01
01:53
Revised date/time functions - now broken out into a separate source file. See the DateAndTimeFunctions wiki page for additional information. (CVS 1116) check-in: 68ef9b45 user: drh tags: trunk
Changes
Hide Diffs Side-by-Side Diffs Ignore Whitespace Patch

Changes to www/nulls.tcl.

     1      1   #
     2      2   # Run this script to generated a nulls.html output file
     3      3   #
     4         -set rcsid {$Id: nulls.tcl,v 1.4 2003/08/13 11:29:24 drh Exp $}
            4  +set rcsid {$Id: nulls.tcl,v 1.5 2003/11/08 12:07:01 drh Exp $}
     5      5   
     6      6   puts {<html>
     7      7   <head>
     8      8   <title>NULL Handling In SQLite Versus Other Database Engines</title>
     9      9   </head>
    10     10   <body bgcolor="white">
    11     11   <h1 align="center">
................................................................................
   166    166   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   167    167   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   168    168   </tr>
   169    169   </table>
   170    170   
   171    171   <table border=1 cellpadding=3 width="100%">
   172    172   <tr><th>&nbsp&nbsp;</th>
   173         -<th>MySQL</th>
          173  +<th>MySQL<br>3.23.41</th>
          174  +<th>MySQL<br>4.0.16</th>
   174    175   <th>Firebird</th>
   175         -<th>SQL Anywhere</th>
   176         -<th>Borland Interbase</th>
          176  +<th>SQL<br>Anywhere</th>
          177  +<th>Borland<br>Interbase</th>
   177    178   </tr>
   178    179   
   179    180   <tr><td>Adding anything to null gives null</td>
          181  +<td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   180    182   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   181    183   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   182    184   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   183    185   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   184    186   </tr>
   185    187   <tr><td>Multiplying null by zero gives null</td>
   186    188   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   187    189   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   188    190   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   189    191   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
          192  +<td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   190    193   </tr>
   191    194   <tr><td>nulls are distinct in a UNIQUE column</td>
          195  +<td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   192    196   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   193    197   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   194    198   <td valign="center" align="center" bgcolor="#aaaad2">(Note 4)</td>
   195    199   <td valign="center" align="center" bgcolor="#aaaad2">(Note 4)</td>
   196    200   </tr>
   197    201   <tr><td>nulls are distinct in SELECT DISTINCT</td>
          202  +<td valign="center" align="center" bgcolor="#c7a9a9">No</td>
   198    203   <td valign="center" align="center" bgcolor="#c7a9a9">No</td>
   199    204   <td valign="center" align="center" bgcolor="#c7a9a9">No (Note 1)</td>
   200    205   <td valign="center" align="center" bgcolor="#c7a9a9">No</td>
   201    206   <td valign="center" align="center" bgcolor="#c7a9a9">No</td>
   202    207   </tr>
   203    208   <tr><td>nulls are distinct in a UNION</td>
   204    209   <td valign="center" align="center" bgcolor="#aaaad2">(Note 3)</td>
          210  +<td valign="center" align="center" bgcolor="#c7a9a9">No</td>
   205    211   <td valign="center" align="center" bgcolor="#c7a9a9">No (Note 1)</td>
   206    212   <td valign="center" align="center" bgcolor="#c7a9a9">No</td>
   207    213   <td valign="center" align="center" bgcolor="#c7a9a9">No</td>
   208    214   </tr>
   209    215   <tr><td>"CASE WHEN null THEN 1 ELSE 0 END" is 0?</td>
          216  +<td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   210    217   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   211    218   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   212    219   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   213    220   <td valign="center" align="center" bgcolor="#aaaad2">(Note 5)</td>
   214    221   </tr>
   215    222   <tr><td>"null OR true" is true</td>
   216    223   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   217    224   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   218    225   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   219    226   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
          227  +<td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   220    228   </tr>
   221    229   <tr><td>"not (null AND false)" is true</td>
   222    230   <td valign="center" align="center" bgcolor="#c7a9a9">No</td>
          231  +<td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   223    232   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   224    233   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   225    234   <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td>
   226    235   </tr>
   227    236   </table>
   228    237   
   229    238   <table border=0 align="right" cellpadding=0 cellspacing=0>
................................................................................
   233    242   <td>Older versions of firebird omits all NULLs from SELECT DISTINCT
   234    243   and from UNION.</td>
   235    244   </tr>
   236    245   <tr><td>2.&nbsp;</td>
   237    246   <td>Test data unavailable.</td>
   238    247   </tr>
   239    248   <tr><td>3.&nbsp;</td>
   240         -<td>The version of MySQL tested (3.23.41) does not support UNION.</td>
          249  +<td>MySQL version 3.23.41 does not support UNION.</td>
   241    250   </tr>
   242    251   <tr><td>4.&nbsp;</td>
   243    252   <td>SQL Anywhere and Borland Interbase 
   244    253   do not allow NULLs in a UNIQUE column.</td>
   245    254   </tr>
   246    255   <tr><td>5.&nbsp;</td>
   247    256   <td>Borland Interbase does not support CASE expressions.</td>