# Datatype not changing in MYSQL database

**URL:** <https://forum.inductiveautomation.com/t/datatype-not-changing-in-mysql-database/74210>\
**Category:** General Discussion\
**Created:** [May 26, 2023, 6:20am UTC](https://forum.inductiveautomation.com/t/datatype-not-changing-in-mysql-database/74210 "2023-05-26T06:20:17Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Faisal\_Shaikh](https://avatars.discourse-cdn.com/v4/letter/f/3ec8ea/32.png) [@Faisal\_Shaikh](https://forum.inductiveautomation.com/u/Faisal_Shaikh)\
**Post date:** [May 26, 2023, 6:20am UTC](https://forum.inductiveautomation.com/t/datatype-not-changing-in-mysql-database/74210/1 "2023-05-26T06:20:17Z")

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Hi,  
I want to change the datatype 't\_stamp' to datetime format,  
But its not allowing to me change and by default the tables got created with datatype as 'BigInt'.

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<div class="post-metadata">

**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\
**Post date:** [May 26, 2023, 7:11am UTC](https://forum.inductiveautomation.com/t/datatype-not-changing-in-mysql-database/74210/2 "2023-05-26T07:11:51Z")

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If you change the datatype then the historian won't be able to write to it. `t_stamp` is an integer and stored in milliseconds since 1970-01-01 00:00:00. t\_stamp values are stored in UTC so that you don't have to worry about timezones and daylight savings. This is common in database applications and the correct way to do it.

t\_stamp values are converted to human-readable datetime formats at the point of display by the "rendering" mode of the component displaying the value.