c#操作sql数据库

常用语句 备用

命名空间:

using System.Data.SqlClient;

连接打开数据库

SqlConnection conn = new SqlConnection("Data Source=计算机名;Initial Catalog=数据库名;User ID=帐号;Password=密码;");
            conn.Open();

用完之后记得

conn.close();

查询

SqlDataAdapter adapter = new SqlDataAdapter();
            SqlCommand cmdSelect = new SqlCommand("select * from 表名  where 字段名=" + 值);
            cmdSelect.Connection = conn;
            adapter.SelectCommand = cmdSelect;


            DataSet ds = new DataSet();
            adapter.Fill(ds);


            foreach (DataRow row in ds.Tables[0].Rows)
            {
            string a=row[0].tostring();
            string b=row["id"].tostring();




              }

更新删除等：        

SqlCommand cmd = new SqlCommand(sqlStr, conn);
                //MessageBox.Show(sqlStr);
                cmd.ExecuteScalar();

查询数量：

string sqlStr = "select count(*) from 表名  where 字段名='" +值 + "'";
                    SqlCommand cmd = new SqlCommand(sqlStr, conn);
                    //MessageBox.Show(sqlStr);
                    string  count=cmd.ExecuteScalar().ToString();