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Frequent Visitor
Posts: 7
Registered: ‎01-16-2019
Accepted Solution

replace null values with content from another column based on condition

I have 20 million rows loaded. I want to replace null values from Column B. The value to be replaced will depends on what value is indicated on the column a.

 

Example:

For null values,

 

1 = W

4 = E

 

and so on..

 

2019-01-17_11-08-56.png


Please take note that null values are many. And the null values is not limited to two only. 

 

Just new to power bi desktop. please guide me. How should I do this?


Accepted Solutions
Community Support Team
Posts: 7,619
Registered: ‎05-02-2017

Re: replace null values with content from another column based on condition

[ Edited ]

Hi @dorothybl,

 

Did you get any error messages? Or it returns wrong results? 

Maybe this one.

Result_Column =
IF (
    [Column B] = blank(),
    LOOKUPVALUE (
        'FixTable'[Letter],
        'FixTable'[Number], [Column A]
    ),
    [Column B]
)

 

 

Best Regards,

Community Support Team _ Dale
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

View solution in original post


All Replies
Super User
Posts: 3,919
Registered: ‎01-14-2017

Re: replace null values with content from another column based on condition

Hi,

 

Create a lookup table and then join your existing Table with the look up Table.

Frequent Visitor
Posts: 7
Registered: ‎01-16-2019

Re: replace null values with content from another column based on condition

apologies but i cannot figure out how should i make a look up table for this.

i have 20 millions rows.

Super User
Posts: 3,919
Registered: ‎01-14-2017

Re: replace null values with content from another column based on condition

Hi,

 

Since there are multiple null values, you will have to tell the software what should go in place of each such cell.  So there will have to be an input table of 2 columns with column 1 values from your existing table.  The second column should be the result you want.

Community Support Team
Posts: 7,619
Registered: ‎05-02-2017

Re: replace null values with content from another column based on condition

Hi @dorothybl,

 

Where are all the replacements? In other words, where is "1 = W 4 = E" from? It could be like this one.

 

Result_Column =
IF (
    ISBLANK ( [Column B] ),
    LOOKUPVALUE (
        'replacementsTable'[result],
        'replacementsTable'[Column A], [Column A]
    ),
    [Column B]
)

 

Best Regards,

Community Support Team _ Dale
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
Frequent Visitor
Posts: 7
Registered: ‎01-16-2019

Re: replace null values with content from another column based on condition

[ Edited ]

Hi @v-jiascu-msft

 

it will come from a separate table called "FixTable" and here is the sample data inside it. Data in the "FixTable" are only those numbers with blank letters.

 

2019-01-18_14-19-40.jpg

 

I tried using your code but it did not work. can you check what was wrong with it?

 

Result_Column =
IF (
    ISBLANK ( [Column B] ),
    LOOKUPVALUE (
        'FixTable'[Letter],
        'FixTable'[Number], [Column A]
    ),
    [Column B]
)
Community Support Team
Posts: 7,619
Registered: ‎05-02-2017

Re: replace null values with content from another column based on condition

[ Edited ]

Hi @dorothybl,

 

Did you get any error messages? Or it returns wrong results? 

Maybe this one.

Result_Column =
IF (
    [Column B] = blank(),
    LOOKUPVALUE (
        'FixTable'[Letter],
        'FixTable'[Number], [Column A]
    ),
    [Column B]
)

 

 

Best Regards,

Community Support Team _ Dale
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
Frequent Visitor
Posts: 7
Registered: ‎01-16-2019

Re: replace null values with content from another column based on condition

hey it works! thanks @v-jiascu-msft