# Delete all rows contained in a dataframe, as specified by an array of ids

**URL:** https://discourse.julialang.org/t/delete-all-rows-contained-in-a-dataframe-as-specified-by-an-array-of-ids/56874
**Category:** New to Julia
**Created:** [March 10, 2021, 1:01pm UTC](https://discourse.julialang.org/t/delete-all-rows-contained-in-a-dataframe-as-specified-by-an-array-of-ids/56874 "2021-03-10T13:01:51Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![Nash](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nash/32/14482_2.png) [@Nash](https://discourse.julialang.org/u/Nash)
#### Post date: [March 10, 2021, 1:01pm UTC](https://discourse.julialang.org/t/delete-all-rows-contained-in-a-dataframe-as-specified-by-an-array-of-ids/56874/1 "2021-03-10T13:01:51Z")

</div>

Using

```
ids = findall(nonunique(mydata))

```

I have found the ids of all rows that are duplicates. Now, I want to clean mydata by erasing the duplicate rows.

How is that done?

---

<div class="post-metadata">

### Author: ![Christopher\_Fisher](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/christopher_fisher/32/26132_2.png) [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)
#### Post date: [March 10, 2021, 1:20pm UTC](https://discourse.julialang.org/t/delete-all-rows-contained-in-a-dataframe-as-specified-by-an-array-of-ids/56874/2 "2021-03-10T13:20:17Z")

</div>

Here is one approach:

`df = df[Not(ids), :]`

---

<div class="post-metadata">

### Author: ![Rudi79](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rudi79/32/3884_2.png) [@Rudi79](https://discourse.julialang.org/u/Rudi79)
#### Post date: [March 10, 2021, 1:23pm UTC](https://discourse.julialang.org/t/delete-all-rows-contained-in-a-dataframe-as-specified-by-an-array-of-ids/56874/3 "2021-03-10T13:23:20Z")

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Or

```julia
df = unique(df)

```

---

<div class="post-metadata">

### Author: ![sijo](https://avatars.discourse-cdn.com/v4/letter/s/da6949/32.png) [@sijo](https://discourse.julialang.org/u/sijo)
#### Post date: [March 10, 2021, 2:32pm UTC](https://discourse.julialang.org/t/delete-all-rows-contained-in-a-dataframe-as-specified-by-an-array-of-ids/56874/4 "2021-03-10T14:32:42Z")

</div>

To do the same by modifying the existing dataframe:

```julia
delete!(df, ids)

```

or directly with the boolean array

```julia
delete!(df, nonunique(df))

```

or simply

```julia
unique!(df)

```