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Overview
Comment: | Update the null-handling document to show how SQL Anywhere and Borland Interbase deal with NULLs. (CVS 1043) |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
9a87f2f326d7fc8bb9f832d0e3fd3114 |
User & Date: | drh 2003-07-01 01:16:30.000 |
Context
2003-07-01
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18:13 | Make sure indices in ATTACH-ed databases are put into the right hash table. Ticket #354. (CVS 1044) (check-in: eb4582831d user: drh tags: trunk) | |
01:16 | Update the null-handling document to show how SQL Anywhere and Borland Interbase deal with NULLs. (CVS 1043) (check-in: 9a87f2f326 user: drh tags: trunk) | |
2003-06-30
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10:36 | Documentation change: refer users to the wiki for additional unsupported features rather than have them send me e-mail. (CVS 1042) (check-in: a3920b0804 user: drh tags: trunk) | |
Changes
Changes to www/nulls.tcl.
1 2 3 | # # Run this script to generated a nulls.html output file # | | | 1 2 3 4 5 6 7 8 9 10 11 | # # Run this script to generated a nulls.html output file # set rcsid {$Id: nulls.tcl,v 1.2 2003/07/01 01:16:30 drh Exp $} puts {<html> <head> <title>NULL Handling In SQLite Versus Other Database Engines</title> </head> <body bgcolor="white"> <h1 align="center"> |
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63 64 65 66 67 68 69 | <tr><th>  </th> <th>SQLite</th> <th>PostgreSQL</th> <th>Oracle</th> <th>Informix</th> <th>DB2</th> <th>MS-SQL</th> | < < < > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > < < < < | | < < < < | | < < < < | | | < < < < | < < < < | | < < < < | | < < < < | | > | > > > > > > > > | 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 | <tr><th>  </th> <th>SQLite</th> <th>PostgreSQL</th> <th>Oracle</th> <th>Informix</th> <th>DB2</th> <th>MS-SQL</th> </tr> <tr><td>Adding anything to null gives null</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> </tr> <tr><td>Multiplying null by zero gives null</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> </tr> <tr><td>nulls are distinct in a UNIQUE index</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> </tr> <tr><td>nulls are distinct in SELECT DISTINCT</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> </tr> <tr><td>nulls are distinct in a UNION</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> </tr> <tr><td>"CASE WHEN null THEN 1 ELSE 0 END" is 0?</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> </tr> <tr><td>"null OR true" is true</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> </tr> <tr><td>"not (null AND false)" is true</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> </tr> </table> <table border=1 cellpadding=5 width="100%"> <tr><th>  </th> <th>MySQL</th> <th>OCELOT</th> <th>Firebird</th> <th>SQL Anywhere</th> <th>Borland Interbase</th> </tr> <tr><td>Adding anything to null gives null</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> </tr> <tr><td>Multiplying null by zero gives null</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> </tr> <tr><td>nulls are distinct in a UNIQUE index</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#aaaad2">(Note 4)</td> <td valign="center" align="center" bgcolor="#aaaad2">(Note 4)</td> </tr> <tr><td>nulls are distinct in SELECT DISTINCT</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#aaaad2">(Note 1)</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> </tr> <tr><td>nulls are distinct in a UNION</td> <td valign="center" align="center" bgcolor="#aaaad2">(Note 3)</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#aaaad2">(Note 1)</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> </tr> <tr><td>"CASE WHEN null THEN 1 ELSE 0 END" is 0?</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#aaaad2">(Note 2)</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#aaaad2">(Note 5)</td> </tr> <tr><td>"null OR true" is true</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> </tr> <tr><td>"not (null AND false)" is true</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#c7a9a9">No</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> <td valign="center" align="center" bgcolor="#a9c7a9">Yes</td> </tr> </table> <table border=0 align="right" cellpadding=0 cellspacing=0> <tr> <td valign="top" rowspan=5>Notes: </td> <td>1. </td> <td>Firebird omits all NULLs from SELECT DISTINCT and from UNION.</td> </tr> <tr><td>2. </td> <td>Test data unavailable.</td> </tr> <tr><td>3. </td> <td>The version of MySQL tested (3.23.41) does not support UNION.</td> </tr> <tr><td>4. </td> <td>SQL Anywhere and Borland Interbase do not allow NULLs in a UNIQUE column.</td> </tr> <tr><td>5. </td> <td>Borland Interbase does not support CASE expressions.</td> </tr> </table> <br clear="both"> <p> </p> <p> The following script was used to gather information for the table above. |
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