How I can send null values in Geography SQL Server field if allow NULL, with SqlParameter and SQL Server Types SqlGeography in C#?

Question

According to the following solution (https://stackoverflow.com/a/42976399/2825284):

cmd.Parameters.Add(new SqlParameter("@position", position) { UdtTypeName = "Geography" });

My code:

SqlGeography geographyfield = null;
sqlParameter.ParameterName = "@geographyfield";
sqlParameter.UdtTypeName = "Geography";

if (geographyfield != null)
    sqlParameter.Value = geographyfield;
else
    sqlParameter.Value = DBNull.Value; // or null, I get the same error

How I can send null values in Geography field if allow NULL?

I get this error:

UdtTypeName property must be set only for UDT parameters.

[`SqlGeography.Null`](https://learn.microsoft.com/dotnet/api/microsoft.sqlserver.types.sqlgeography.null). — Jeroen Mostert, Sep 19 '20 at 18:08

score 0 · Answer 1 · answered Sep 19 '20 at 18:14

0

One option can be set data has min value or another unexpected value that you can take like a null or unset value. Is in sql value set this field has nullable?

answered Sep 19 '20 at 18:14

Leo

1

Yes, with Jeroen Mostert's comment is the solution: SqlGeography.Null. Thanks. – Ejrr1085 Sep 19 '20 at 18:19

score 0 · Accepted Answer · answered Sep 19 '20 at 18:25

0

According Jeroen Mostert's comment this is the solution: SqlGeography.Null.

SqlGeography geographyfield = null;
sqlParameter.ParameterName = "@geographyfield";
sqlParameter.UdtTypeName = "Geography";

if (geographyfield != null)
    sqlParameter.Value = geographyfield;
else
    sqlParameter.Value = SqlGeography.Null;

Thanks Jeroen Mostert.

answered Sep 19 '20 at 18:25

Ejrr1085

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1

This can be written more succinctly as `sqlParameter.Value = geographyfield ?? SqlGeography.Null`. – Jeroen Mostert Sep 19 '20 at 18:33

How I can send null values in Geography SQL Server field if allow NULL, with SqlParameter and SQL Server Types SqlGeography in C#?

2 Answers2