Hi Guys,
   A problem has developed with one of my database scripts. Under heavy loads it's duplicating data. I'm sure there must be a way of locking the database until the connection is closed. Here is roughly what happens.

A Open database connection
B read X from table A
C write X to table A if X doesn't exist
D Close connection

It appears that if the script is called with X twice at practically the same time under heavy server loads. The data is written twice. I guess the scripts are running in line and are doing B before either hit C.
How can I lock the database or table so that the scripts can only read and write when it's open?
Also what will happen if a script tries to read the table and it's locked? Will it wait or error? How can I make it wait.

Sorry for all the questions. My current project is requiring a lot of advanced code, stuff most perl tutorials don't seem to cover.
I greatly appreciate everyones help!

Lyle

In reply to Locking a database connection by cosmicperl

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