# SQLTag Real Time Provider (Mysql) bidirectionnal use

**URL:** <https://forum.inductiveautomation.com/t/sqltag-real-time-provider-mysql-bidirectionnal-use/3319>\
**Category:** Ignition\
**Created:** [September 22, 2011, 4:23pm UTC](https://forum.inductiveautomation.com/t/sqltag-real-time-provider-mysql-bidirectionnal-use/3319 "2011-09-22T16:23:42Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\
**Post date:** [September 22, 2011, 4:23pm UTC](https://forum.inductiveautomation.com/t/sqltag-real-time-provider-mysql-bidirectionnal-use/3319/1 "2011-09-22T16:23:42Z")

</div>

I try to have a bidirectionnal binding of SQLTag :

SQLTag Real Time Provider : Mysql DB

When I write the tag from ignition HMI, it’s OK in sqlt\_core  
When i write the intvalue and valuechange (datetime = CURRENT\_TIMESTAMP()) from sql update with the mysql console,the readed value is ok in the ignition database query browser, but the value is not resfred on the ignition HMI ???

Do I write correctly the good field of sqlt\_core ?  
is this operation allowed ??  
(My ignition gateway is in full read/write communication mode)

Please help ![:prayer:](https://us1.discourse-cdn.com/inductiveautomation/original/1X/e5a7e3b63facc151ea73e3b45db7bdb3d4bdc316.gif ":prayer:")

---

<div class="post-metadata">

**Author:** ![Colby.Clegg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/colby.clegg/32/3282_2.png) [@Colby.Clegg](https://forum.inductiveautomation.com/u/Colby.Clegg)\
**Post date:** [September 22, 2011, 5:44pm UTC](https://forum.inductiveautomation.com/t/sqltag-real-time-provider-mysql-bidirectionnal-use/3319/2 "2011-09-22T17:44:20Z")

</div>

That should work fine, as long as the tag is configured as a static DB tag. In other words, the tag is a “DB Tag” type (tagtype column = 1, in the sqlt\_core table), and its expression mode is set to “none”.

If it’s an OPC tag, writes must be sent through the sqlt\_wq table. Note: the tables are described in a white paper that you can find [in this thread](http://www.inductiveautomation.com/forum/viewtopic.php?f=25&t=5054&p=11655).

In short, it definitely should be possible. Let me know if your tag type is correct, and we can go from there.

Regards,

---

<div class="post-metadata">

**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\
**Post date:** [September 22, 2011, 8:37pm UTC](https://forum.inductiveautomation.com/t/sqltag-real-time-provider-mysql-bidirectionnal-use/3319/3 "2011-09-22T20:37:15Z")

</div>

I check (tagtype column = 1, in the sqlt\_core table), and its expression mode is set to “none”.  
it’s ok, have you other config to check ?

---

<div class="post-metadata">

**Author:** ![Colby.Clegg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/colby.clegg/32/3282_2.png) [@Colby.Clegg](https://forum.inductiveautomation.com/u/Colby.Clegg)\
**Post date:** [September 23, 2011, 3:53pm UTC](https://forum.inductiveautomation.com/t/sqltag-real-time-provider-mysql-bidirectionnal-use/3319/4 "2011-09-23T15:53:12Z")

</div>

First off, you’re not using the 7.3 beta, right? Because that acts a bit differently (all writes go through the write queue).

If 7.2, perhaps (for the sake of testing) try increasing the “poll overlap” to a higher number, like 10 seconds. Having this number high is not what you want to run forever, but it might help narrow things down. I have to imagine your table doesn’t have much in it, but if for some reason it was taking over 1 second to write/read the row, it might be missed.

A few other things:

- Is the database on the same machine?
- If you set configchange to CURRENT\_TIMESTAMP, does the tag reload? (you’ll want the tag to be displayed in the designer first to see… or watch the tag load stats in the gateway under Status\>SQLTags)

There are a number of people who drive their own SQLTags externally in this manner, so I don’t think there’s anything actually wrong in the software… we just need to track down the missing link! 🙂

Regards,