cannot set column int to be null. please use dbnull instead in datarow

Question

I am fetching data from datarow and facing issue when there is null value in a row column. How can I change the below mentioned code to read null values??

Datarow dr_Out[j] = dr1.Field<double?>("" + Convert.ToString(columnNames[j]) + "");

at this line when there is null value below error occur.

cannot set column int to be null. please use dbnull instead in datarow

after adding DBNull facing this

Try adding ?? (object)DbNull.Value to the end

juharr
– juharr

2020-03-11 15:23:42 +00:00
Commented Mar 11, 2020 at 15:23 — juharr
– juharr, Commented Mar 11, 2020 at 15:23
?? (object)DBNull.Value

st_stefanov
– st_stefanov

2020-03-11 15:35:42 +00:00
Commented Mar 11, 2020 at 15:35 — st_stefanov
– st_stefanov, Commented Mar 11, 2020 at 15:35

st_stefanov · Accepted Answer · 2020-03-11 15:35:07Z

4

You can do as suggested by the error:

    dr_Out[j] = DBNull.Value;
    double? myValue = dr1.Field<double?>("" + Convert.ToString(columnNames[j]) + "");

    if(myValue != null)
    {
        dr_Out[j] = myValue;
    }

edited Mar 11, 2020 at 15:35

answered Mar 11, 2020 at 15:26

st_stefanov

1,1961 gold badge10 silver badges31 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

MohsiniJan Over a year ago

This will skip my step, my need is if there is null value then read that null and pass null value

st_stefanov Over a year ago

And you need to write DBNull (capital B)

Alberto Rechy · Accepted Answer · 2024-12-09 23:19:56Z

1

I always define my classes to accept nulls.

eg:

public DateTime? updatedTime { get; set; }

and compare for nulls in the code.

dr["updatedTime"] = (e.updatedTime is null) ? (object)DBNull.Value : (object)e.updatedTime.Value;

this way it forces a "proper" null suitable for DBs.

edited Dec 9, 2024 at 23:19

Alberto Rechy

1571 silver badge12 bronze badges

answered Oct 5, 2023 at 1:53

Fandango68

4,9555 gold badges50 silver badges88 bronze badges

Collectives™ on Stack Overflow

cannot set column int to be null. please use dbnull instead in datarow

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related