[求助]如何在SQL查询语句中加入双引号???

private void getgrid(string sql)
{
try
{
//char a='"';
//char b='"';
//string x=Convert.ToString(a);
//string y=Convert.ToString(a);
//string SQL=@""+sql+"";
string strSQL ="";
DataSet datgrid=new DataSet();
strSQL="exec get_ItUser \""+sql+"\"";//这里加入双引号用 \" 不成功
datgrid = datcns.ExeDatset(strSQL);
MyDataGrid1.Dispose();
MyDataGrid1.DataSource=datgrid.Tables[0];
MyDataGrid1.DataBind();
}
catch(Exception ex)
{
WebUtil.msg(ex.ToString());
}

}
sql= " AND B.b_deliverydate>='" + stadate.Value.Trim() + "' and B.b_deliverydate<='" + endDate.Value.Trim() + "'";