In several examples now I have seen the KEY command in mysql used, for example
I have searched in the mysql manual but I can't seem to find it. It is driving me nuts... can you help me understand what it is, what it does and the syntax to use with it?
two things to (try to) remember --
first, KEY is totaly different from PRIMARY KEY and FOREIGN KEY
second, KEY is a (non-standard) mysql synonym for INDEX
you will find KEY mentioned in da manual under CREATE TABLE
Thanks, that was great. I found
KEY is normally a synonym for INDEX. The key attribute PRIMARY KEY can also be specified as just KEY when given in a column definition. This was implemented for compatibility with other database systems.
So if it is non-standard, why have I seen in in two places people are describing how to set up mysql databases? One of them as mentioned above on Sitepoint? I am still curious.
standard sql and mysql sql are different, that's all
mysql supports most of standard sql (not all), and also has its own proprietary extensions to standard sql
With mysql can I do something to add a 'KEY' to an existing table? Like...
UPDATE TABLE MyTable SET KEY 'author_id' ('author_id');
Or will that do something harmful to MyTable?
that's close, you got the idea, except for the correct syntax
ALTER TABLE MyTable ADD KEY author_id (author_id);
notice no quotes around the index name or column name
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