假设链接字符串如下:
Server=.;database=mydb;uid=sa;pwd=123456
数据表为MyTable
以下这个方法用于判断
public static bool isReEmail(string email)
{
using (SqlConnection conn = new SqlConnection("Server=.;database=mydb;uid=sa;pwd=123456"))
{
SqlCommand cmd = new SqlCommand();
cmd.CommandText = "Select count(*) From MyTable Where Email=@Email";
cmd.CommandType = CommandType.Text;
cmd.Connection = conn;
cmd.Parameters.Add("@Email", SqlDbType.VarChar, 50).Value = email;
conn.Open();
int n = Convert.ToInt32(cmd.ExecuteScalar());
if (n > 0)
{
return true;
}
else
{
return false;
}
}
}
调用 比如这个方法的类为SqlHelper
SqlHelper.isReEmail("
[email protected]")
调用时返回true的话,表示已有此邮件,返回false,表示没有此邮件