How to set the property to true that will allow me to insert null values?

Question

I got the error in unit testing for the method of "AddEffectiveQuarterTest". How to set the property to true that will allow me to insert null values?

AvailabilityBLTest.cs file : "AddEffectiveQuarterTest" method

    public void AddEffectiveQuarterTest()
    {
        AvailabilityBL target = new AvailabilityBL();
        AvailabilityDS ds = new AvailabilityDS();
        TestBusinessLogic.BusinessLogic_AvailabilityBLAccessor accessor = new TestBusinessLogic.BusinessLogic_AvailabilityBLAccessor(target);

        // SETUP STANDARD TEST DATA
        this.SetupTestData(ds, null);
        int newModelID = -1;    
        .........
    }

AvailabilityDS.Designer.cs file

public string QuarterDisplay {
    get {
            try {
                return ((string)(this[this.tableTime.QuarterDisplayColumn]));
            }
            catch (global::System.InvalidCastException e) {
                throw new global::System.Data.StrongTypingException("The value for column \'QuarterDisplay\' in table \'Time\' is DBNull.", e);
        }
    }
    set {
            this[this.tableTime.QuarterDisplayColumn] = value;
    }
}

How do I edit with the following code to set the property to true that will allow me to insert null values?

public bool AllowDBNull { get; set; }

How do I check the dbnull? I got the error with the following code.

 public bool IsColumnNameNull() {
                    return this.IsNull(this.tableColumn.ColumnNameColumn);
                }

 public string SetColumnKeyNull() {
            {
                get
                {
                    try
                    {
                        return ((string)(this[this.tableColumn.ColumnKeyColumn]));
                    }
                    catch (global::System.InvalidCastException e)
                    {
                        throw new global::System.Data.StrongTypingException("The value for column \'SetColumnKeyNull\' in table \'Column\' is DBNull.", e);
                    }
                }
                set
                {
                    this[this.tableColumn.ColumnKeyColumn] = value;
                }
            }

Answer 1

You appear to be using a strongly-typed DataSet.

In this case, the generated code will contain methods to set fields to null.

For example, if your field QuarterDisplay allows DBNull, the generated code in AvailabilityDS.Designer.cs will include a method SetQuarterDisplayNull(). It will also include a method IsQuarterDisplayNull() that you can use to check for a DBNull value.