Hey all -
I'm trying to implement a basic log in a table. Instead of writing to a text
file on the server, I want to insert entries into a 'log' table. However, I
want to limit this table to only have the last 500 rows or so. How do I do
this?
Here's my pseudocode, but it seems as if there would be a better way:
logEntry($messa ge){
insert message into table
get number of rows in table
if (numrows > 500){
delete from table where ((numrows - id) > 500)
}
}
Is that right??
Thanks,
Shane 6 1662
Shane Niebergall wrote: Hey all -
I'm trying to implement a basic log in a table. Instead of writing to a text file on the server, I want to insert entries into a 'log' table. However, I want to limit this table to only have the last 500 rows or so. How do I do this?
Here's my pseudocode, but it seems as if there would be a better way:
This would be easy to do with PHP but I'm not sure if you want to use
PHP...IMHO logEntry($messa ge){ insert message into table get number of rows in table if (numrows > 500){ delete from table where ((numrows - id) > 500) } }
Is that right??
Thanks, Shane
I will be using PHP - how will that make it easier?
Thanks,
Shane
"Hal Halloway" <Ha******@nospa m.net> wrote in message
news:REUJd.253$ u45.160@trnddc0 8... Shane Niebergall wrote:
Hey all -
I'm trying to implement a basic log in a table. Instead of writing to a
text file on the server, I want to insert entries into a 'log' table.
However, I want to limit this table to only have the last 500 rows or so. How do I
do this?
Here's my pseudocode, but it seems as if there would be a better way:
This would be easy to do with PHP but I'm not sure if you want to use PHP...IMHO
logEntry($messa ge){ insert message into table get number of rows in table if (numrows > 500){ delete from table where ((numrows - id) > 500) } }
Is that right??
Thanks, Shane
Shane Niebergall wrote: logEntry($messa ge){ insert message into table get number of rows in table if (numrows > 500){ delete from table where ((numrows - id) > 500) } }
I'd do the delete before I do the insert, if you want the number of rows
never to exceed 500. Also, you only need to delete one row if your
$message always results in inserting one row.
logEntry($messa ge){
get number of rows in table
if numrows = 500 {
delete first row of table
}
insert $message into table
}
Be careful about multiple clients doing this operation simultaneously;
you might want to lock the table. See the docs on LOCK TABLES.
Also you can specify the MAX_ROWS in your CREATE TABLE statement if you
want MySQL to enforce it! See the docs of the CREATE TABLE statement.
Regards,
Bill K.
Hi Bill -
Thanks for the tips. Do you mind expanding on this:
"delete first row of table"
How would that delete query look?
Thanks so much!
Shane
"Bill Karwin" <bi**@karwin.co m> wrote in message
news:ct******** *@enews1.newsgu y.com... Shane Niebergall wrote: logEntry($messa ge){ insert message into table get number of rows in table if (numrows > 500){ delete from table where ((numrows - id) > 500) } }
I'd do the delete before I do the insert, if you want the number of rows never to exceed 500. Also, you only need to delete one row if your $message always results in inserting one row.
logEntry($messa ge){ get number of rows in table if numrows = 500 { delete first row of table } insert $message into table }
Be careful about multiple clients doing this operation simultaneously; you might want to lock the table. See the docs on LOCK TABLES.
Also you can specify the MAX_ROWS in your CREATE TABLE statement if you want MySQL to enforce it! See the docs of the CREATE TABLE statement.
Regards, Bill K.
Shane Niebergall wrote: Thanks for the tips. Do you mind expanding on this: "delete first row of table"
How would that delete query look?
This could do it:
delete from myTable where primary_key_id =
(select min(primary_key _id) from myTable)
Regards,
Bill K.
Perfect - exactly what I was looking for. Thanks Bill!!
"Bill Karwin" <bi**@karwin.co m> wrote in message
news:ct******** *@enews3.newsgu y.com... Shane Niebergall wrote: Thanks for the tips. Do you mind expanding on this: "delete first row of table"
How would that delete query look?
This could do it:
delete from myTable where primary_key_id = (select min(primary_key _id) from myTable)
Regards, Bill K. This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
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