# Transaction group expression/SQL item

**URL:** <https://forum.inductiveautomation.com/t/transaction-group-expression-sql-item/16984>\
**Category:** Ignition\
**Created:** [February 14, 2018, 11:52am UTC](https://forum.inductiveautomation.com/t/transaction-group-expression-sql-item/16984 "2018-02-14T11:52:23Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Claus\_Nielsen](https://avatars.discourse-cdn.com/v4/letter/c/77aa72/32.png) [@Claus\_Nielsen](https://forum.inductiveautomation.com/u/Claus_Nielsen)\
**Post date:** [February 14, 2018, 11:52am UTC](https://forum.inductiveautomation.com/t/transaction-group-expression-sql-item/16984/1 "2018-02-14T11:52:23Z")

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Trying to set up an expression/SQL item in a transaction group and having problems doing something like the snippet below.

```auto
SELECT DATE_SUB({[~]Last Time Scheduled}, INTERVAL 1 WEEK)

```

The value always results in evaluation error?

The `{[~]Last Time Scheduled}` is another SQL expression item in the group which currently just does the following and stores the result as a string.

```auto
SELECT NOW()

```

Replacing the “tag” with a string datetime or `NOW()` solves the problem, but why can’t I use a tag value?

Using MySQL server.

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<div class="post-metadata">

**Author:** ![JordanCClark](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jordancclark/32/83362_2.png) [@JordanCClark](https://forum.inductiveautomation.com/u/JordanCClark)\
**Post date:** [February 14, 2018, 12:21pm UTC](https://forum.inductiveautomation.com/t/transaction-group-expression-sql-item/16984/2 "2018-02-14T12:21:01Z")

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Try putting quotes around it.

`SELECT DATE_SUB('{[~]Last Time Scheduled}', INTERVAL 1 WEEK)`

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<div class="post-metadata">

**Author:** ![Claus\_Nielsen](https://avatars.discourse-cdn.com/v4/letter/c/77aa72/32.png) [@Claus\_Nielsen](https://forum.inductiveautomation.com/u/Claus_Nielsen)\
**Post date:** [February 14, 2018, 12:24pm UTC](https://forum.inductiveautomation.com/t/transaction-group-expression-sql-item/16984/3 "2018-02-14T12:24:26Z")

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Thank you, exactly what was required!

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<div class="post-metadata">

**Author:** ![Claus\_Nielsen](https://avatars.discourse-cdn.com/v4/letter/c/77aa72/32.png) [@Claus\_Nielsen](https://forum.inductiveautomation.com/u/Claus_Nielsen)\
**Post date:** [February 14, 2018, 12:34pm UTC](https://forum.inductiveautomation.com/t/transaction-group-expression-sql-item/16984/4 "2018-02-14T12:34:21Z")

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Actually thought I tried this though.  
Maybe I dropped it as the text is marked as a string (purple text) when quoting it.