Forum Discussion
Cannot Open any more databases
Previously, I have gone right through all of the code and made sure all objects and record-sets were closed and set to nothing when the form was closed. In fact, I can see that this seems to be the case, because when I open and close the forms now, the number of connections reverts to the previous level it was before opening them, so all items have been successfully closed.
The next question is; how do I further reduce the use of connections in my forms. I am obviously building my forms in a way that uses too many connections. How can I reduce that?
As you may already know, Access has a total of 255 available connections.
Each open object with a record source/row source consumes 1 or more connections.
If the number of available connections drops too far, the error message you are getting may occur.
Closing recordsets after use is good practice and, as noted, this should allow Access to recover those connections.
However, your original post stated:
NeilClark wrote:
The system has a number of forms that need to be opened and stay open, so I have them all on large tab control so I can flip between the open forms easily. Most of the forms use combo drop-down boxes as part of the filtering; like a drop-down listing all the staff, so one can be chosen to look at their jobs. And many of the queries under the forms use dynamic lookups to get data from other related tables.
Having all of these open at once is likely to be your issue. How many connections does all of this 'consume'?
Remember that subforms are loaded before the main form. So if you have a number of subforms on your tab control together with combos and dynamic lookups you are going to put Access under stress!
I suggest you only load each form as and when needed and close it when moving to another form / tab
OR only load the recordsource for each subform when it is activated. Similarly for your combos/ queries of possible. Then close each of these or clear the row source / record source when you move to another subform / tab
Hope that helps you move forward
- NeilClarkApr 24, 2021Copper ContributorOK - thanks a lot for your wanting to help - it makes a big difference!
I will see how it works if I close each form when I open a new one. That seems to be the only way out that I can see just now. Will let you know how it goes.- isladogsApr 24, 2021MVPNo problem. Sorry about the delay replying. I was offline most of today.
You didn't say how many connections were being used / how many are remaining before making any change to your app- NeilClarkApr 24, 2021Copper ContributorI did a test run with your little form open, starting with the opening page and then opening the others one-by-one. They each took about 24 to 40 connections, so eventually I ran out of connections and it bombed out.