Query update

[carmelomcc]

i amt rying to subtract what is in an temporary table/column from a regular table/column, then i want to insert that data into another column in the table.

temporary table name = xxx
temporary column name = used_size

Normal table name = chk_info

Table column = used_size

Table column to drop the data into = daily_chg


Code sample:

update chk_info set daily_chg =(xxx.used_size-chk_info.used_size);

[gesf]

Have you tried running that in MySQL ? Do you receive any error messages at all?
If you're using this with php make sure you're not using the same variable for mysql_query.
You should use another one or unset it before re-initializing it with a different value.

Or perhaps it is a key field matter!

[carmelomcc]

It does not work with in the msql client. I can get the code to work when it is within the same table with two columns it works great, but when i work within two tables it fails.