# Query.jl @mutate command does not preserve column types

**URL:** https://discourse.julialang.org/t/query-jl-mutate-command-does-not-preserve-column-types/41231
**Category:** General Usage
**Created:** [June 11, 2020, 9:54pm UTC](https://discourse.julialang.org/t/query-jl-mutate-command-does-not-preserve-column-types/41231 "2020-06-11T21:54:24Z")
**Posts on this page:** 1
**Showing post:** 3

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### Author: ![dlakelan](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dlakelan/32/8491_2.png) [@dlakelan](https://discourse.julialang.org/u/dlakelan)
#### Post date: [June 11, 2020, 10:15pm UTC](https://discourse.julialang.org/t/query-jl-mutate-command-does-not-preserve-column-types/41231/3 "2020-06-11T22:15:10Z")

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Indeed, I noticed this as well here: [Queryverse queries lose type information? - #9 by dlakelan](https://discourse.julialang.org/t/queryverse-queries-lose-type-information/40572/9)

I managed to figure out how to go around this in my case, but didn’t address the bigger issue. WDYT @davidanthoff? I didn’t see anything obvious in the documentation about how to keep the types stable.

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