# Declare Column Data Types in python models

**URL:** <https://discourse.getdbt.com/t/declare-column-data-types-in-python-models/13082>\
**Category:** Help\
**Tags:** bigquery, python-models, dbt-cloud\
**Created:** [April 25, 2024, 9:06pm UTC](https://discourse.getdbt.com/t/declare-column-data-types-in-python-models/13082 "2024-04-25T21:06:11Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![mra](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mra](https://discourse.getdbt.com/u/mra)\
**Post date:** [April 25, 2024, 9:06pm UTC](https://discourse.getdbt.com/t/declare-column-data-types-in-python-models/13082/1 "2024-04-25T21:06:11Z")

</div>

In my python model I have created a data frame with 3 columns, 2 string columns and one is json type.  
When I execute the model, it runs without any error but in my destination big query table , all of the columns are set to string.  
How can I declare the data types in order to dbt detect the json type?

Thanks!