diff options
author | unknown <arjen@fred.bitbike.com> | 2002-05-24 12:14:49 +1000 |
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committer | unknown <arjen@fred.bitbike.com> | 2002-05-24 12:14:49 +1000 |
commit | 9fc5ea9a43210d1d01be9982bf30bc6840cdb0f3 (patch) | |
tree | 54180a276cabd11ec90fd7574457782865af37d7 /Docs | |
parent | 975b37745f2adfc0d8a697f098d3d1ff9a94b797 (diff) | |
download | mariadb-git-9fc5ea9a43210d1d01be9982bf30bc6840cdb0f3.tar.gz |
Fixed outdated statements on NULL indexing and multi-table delete.
Diffstat (limited to 'Docs')
-rw-r--r-- | Docs/manual.texi | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/Docs/manual.texi b/Docs/manual.texi index 50c7a964d6f..e34415f437b 100644 --- a/Docs/manual.texi +++ b/Docs/manual.texi @@ -47547,10 +47547,12 @@ mysql> SELECT * FROM my_table WHERE phone IS NULL; mysql> SELECT * FROM my_table WHERE phone = ""; @end example -In MySQL, as in many other SQL servers, you can't index -columns that can have @code{NULL} values. You must declare such columns -@code{NOT NULL}. Conversely, you cannot insert @code{NULL} into an indexed -column. +Note that you can only add an index on a column that can have @code{NULL} +values if you are using MySQL Version 3.23.2 or newer and are using the +@code{MyISAM} or @code{InnoDB} table type. +In earlier versions and with other table types, you must declare such +columns @code{NOT NULL}. This also means you cannot then insert +@code{NULL} into an indexed column. @findex LOAD DATA INFILE When reading data with @code{LOAD DATA INFILE}, empty columns are updated @@ -47613,9 +47615,9 @@ decide which rows from the result set should be used. @cindex rows, deleting @cindex tables, deleting rows -As MySQL doesn't support sub-selects or use of more than one table -in the @code{DELETE} statement, you should use the following approach to -delete rows from 2 related tables: +As MySQL doesn't yet support sub-selects, nor the use of more than one +table in the @code{DELETE} statement (prior to Version 4.0), you should +use the following approach to delete rows from 2 related tables: @enumerate @item |