Sql Command Error with where condition

Question

I tried using the below sqlcommand statement throwing error at where condition. What's wrong with the statement. Can any one help me please.

 

SqlCommand sqlcmd = new SqlCommand("insert into Database1(ProdcutReleaseDate) values('"+DateTime.Now+"') where [property address]='" + ComboBox1.SelectedValue+"'", sqlcon);

 

 

Thanks

sandeep