# Clarion 12 MSSQL Driver problem opens a dozen connections **URL:** \ **Category:** questions\ **Tags:** mssql, drivers, c12\ **Created:** [May 16, 2025, 3:21pm UTC](https://clarionhub.com/t/clarion-12-mssql-driver-problem-opens-a-dozen-connections/8171 "2025-05-16T15:21:34Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![vlada\_vukicevic](https://clarionhub.com/user_avatar/clarionhub.com/vlada_vukicevic/32/2343_2.png) [@vlada\_vukicevic](https://clarionhub.com/u/vlada_vukicevic)\ **Post date:** [May 16, 2025, 3:21pm UTC](https://clarionhub.com/t/clarion-12-mssql-driver-problem-opens-a-dozen-connections/8171/1 "2025-05-16T15:21:34Z")
Problem with MSSQL driver, the driver opens a dozen connections to the database. It is enough to just log in with the connection string and immediately in the SSMS Activity monitor you will see a dozen sessions started. So far with C11 everything was ok. It is impossible to work like this, MSSQL Server slows down if there are more users and more databases on the server. For now I have stayed on C11. I'm trying to report it on Problem Tracker, but there's no option for C12 yet. ---
**Author:** ![BoxSoft](https://clarionhub.com/letter_avatar_proxy/v4/letter/b/3d9bf3/32.png) [@BoxSoft](https://clarionhub.com/u/BoxSoft)\ **Post date:** [May 17, 2025, 2:01pm UTC](https://clarionhub.com/t/clarion-12-mssql-driver-problem-opens-a-dozen-connections/8171/2 "2025-05-17T14:01:28Z")
Prior versions of Clarion often had trouble maintaining connections, and one of the workarounds was to create a bunch of connections (100, IIRC) at program startup. These were just connections, not actually doing anything, and therefore didn’t strain the server in any way. Perhaps C12 uses a similar approach to work around quirks in SQL Sever (and there are MANY quirks there). 🤷‍♂️ ---
**Author:** ![vlada\_vukicevic](https://clarionhub.com/user_avatar/clarionhub.com/vlada_vukicevic/32/2343_2.png) [@vlada\_vukicevic](https://clarionhub.com/u/vlada_vukicevic)\ **Post date:** [May 17, 2025, 9:31pm UTC](https://clarionhub.com/t/clarion-12-mssql-driver-problem-opens-a-dozen-connections/8171/3 "2025-05-17T21:31:42Z")
I understand what you want to say, but how can I explain to my clients that the application works at least twice as slowly. I tested the application made with C11 and C12 where nothing was changed in the code, the application made with C11 is incomparably fast and works perfectly. ---
**Author:** ![Bruce](https://clarionhub.com/letter_avatar_proxy/v4/letter/b/ccd318/32.png) [@Bruce](https://clarionhub.com/u/Bruce)\ **Post date:** [May 19, 2025, 8:11am UTC](https://clarionhub.com/t/clarion-12-mssql-driver-problem-opens-a-dozen-connections/8171/4 "2025-05-19T08:11:21Z")
Which version of the Microsoft ODBC client for SQL Server do you have installed? ---
**Author:** ![vlada\_vukicevic](https://clarionhub.com/user_avatar/clarionhub.com/vlada_vukicevic/32/2343_2.png) [@vlada\_vukicevic](https://clarionhub.com/u/vlada_vukicevic)\ **Post date:** [May 19, 2025, 8:24am UTC](https://clarionhub.com/t/clarion-12-mssql-driver-problem-opens-a-dozen-connections/8171/5 "2025-05-19T08:24:41Z")
These drivers are installed: - ODBC Driver 17 for SQL Server 2017.1710.06.01 - SQL Server 10.00.19041.5848 - SQL Server Native Client 11.0 2011.110.7515.02 `MESSAGE(Paramet{PROP:ConnectString})` Since I don’t know what clarion uses for connection. I put this line in the code after open files and got the answer `DRIVER=ODBC Driver 17for SQL Server;SERVER=.......` I think then I’m using ODBC Driver and not Native. This is the connection string I’m using `con=clip(clip(Glo:Server)&','&clip(MSBase)&','&clip(Glo:Name)&','&clip(Glo:Password))` While in the dictionary in the table properties: Driver: MSSQL Driver Options: /IGNORETRUNCATION=TRUE /LOGONSCREEN=FALSE Owner Name: !con Create,Threaded and Bindable are checked ---
**Author:** ![Robert\_Scheidl](https://clarionhub.com/user_avatar/clarionhub.com/robert_scheidl/32/5691_2.png) [@Robert\_Scheidl](https://clarionhub.com/u/Robert_Scheidl)\ **Post date:** [May 19, 2025, 11:14am UTC](https://clarionhub.com/t/clarion-12-mssql-driver-problem-opens-a-dozen-connections/8171/6 "2025-05-19T11:14:32Z")
Problem with MSSQL driver, cannot commit delete and app hangs up. There is lot of open transactions with SERIALIZABLE isolation level that locks transaction. I tried with SQL 10.50.4000 and SQL 15.0.2080. Tried also to change ISOLATION LEVEL with no result.