# Calcul entre deux rows

**URL:** <https://community.glideapps.com/t/calcul-entre-deux-rows/74209>\
**Category:** Ask for Help\
**Created:** [June 18, 2024, 5:23pm UTC](https://community.glideapps.com/t/calcul-entre-deux-rows/74209 "2024-06-18T17:23:50Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Steph59270](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/steph59270/32/76698_2.png) [@Steph59270](https://community.glideapps.com/u/Steph59270)\
**Post date:** [June 18, 2024, 5:23pm UTC](https://community.glideapps.com/t/calcul-entre-deux-rows/74209/1 "2024-06-18T17:23:51Z")

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Bonjour,  
Je débute une application de carnet de bord de véhicule et je cherche à faire une soustraction entre deux rows de la glide table pour obtenir le kilométrage effectué durant la journée:

 ![Calcul Glide](https://us1.discourse-cdn.com/flex002/uploads/glideapps/original/3X/9/b/9b9b0c6049c04b906a8301970035d0464ce9df2a.jpeg)

En vous remerciant par avance car mes recherches ne me donne que des calculs sur une même row.

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**Author:** ![Jeff\_Hager](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/jeff_hager/32/43_2.png) [@Jeff\_Hager](https://community.glideapps.com/u/Jeff_Hager)\
**Post date:** [June 18, 2024, 6:49pm UTC](https://community.glideapps.com/t/calcul-entre-deux-rows/74209/2 "2024-06-18T18:49:16Z")

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- Create a rowID column for your table.
- Create a lookup column that points to that rowID, you’ll get an array of rowIDs.
- Use a “find element index” column, find the rowID from the array you created above. You’ll get a list of index for each row, starting from 0.
- Create a math column and subtract 1 from the index.
- Create a single relation column linking the math column to the index column.
- Create a lookup column to get the mileage from the relation.
- Now you can subtract the lookup mileage from the current row’s mileage using a math column.

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**Author:** ![Steph59270](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/steph59270/32/76698_2.png) [@Steph59270](https://community.glideapps.com/u/Steph59270)\
**Post date:** [June 19, 2024, 9:00am UTC](https://community.glideapps.com/t/calcul-entre-deux-rows/74209/3 "2024-06-19T09:00:52Z")

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Merci, j’ai maintenant acquis le principe pour transférer des informations sur la ligne suivante avec une relation mais je récupére la photo et non la valeur numérique des kilomètres.

Lors du calcul de la différence, la somme est nulle car je n’arrive pas à avoir la valeur des kilomètres de la ligne précédente.

 ![Calcul Glide 2](https://us1.discourse-cdn.com/flex002/uploads/glideapps/original/3X/8/0/80e05d10a40bd5d6767de0d72b0f3c6e075dbe85.jpeg)

Les colonnes sont elles maintenant correctes et comment obtenir le résultat ?

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**Author:** ![Jeff\_Hager](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/jeff_hager/32/43_2.png) [@Jeff\_Hager](https://community.glideapps.com/u/Jeff_Hager)\
**Post date:** [June 19, 2024, 11:41am UTC](https://community.glideapps.com/t/calcul-entre-deux-rows/74209/4 "2024-06-19T11:41:13Z")

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I think you missed this step.

> [@Jeff\_Hager](#):
>
> Create a lookup column to get the mileage from the relation

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**Author:** ![Steph59270](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/steph59270/32/76698_2.png) [@Steph59270](https://community.glideapps.com/u/Steph59270)\
**Post date:** [June 21, 2024, 8:23am UTC](https://community.glideapps.com/t/calcul-entre-deux-rows/74209/5 "2024-06-21T08:23:36Z")

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Rebonjour @Jeff_Hager,

Merci pour votre aide, je suis enfin arrivé à trouver le fonctionnement avec “Lookup”, ce n’est pas toujours évident de trouver la bonne fonction quand on travaille avec un traducteur en ligne qui interprète différemment.

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**Author:** ![Jeff\_Hager](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/jeff_hager/32/43_2.png) [@Jeff\_Hager](https://community.glideapps.com/u/Jeff_Hager)\
**Post date:** [June 21, 2024, 1:04pm UTC](https://community.glideapps.com/t/calcul-entre-deux-rows/74209/6 "2024-06-21T13:04:53Z")

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Thank you for letting me know. Whenever I know someone is using a translator, I try to use capital letters or quotes so the Glide functions translate correctly. Sorry that I missed that.