| 先写一个数据库统计函数 
 复制代码 代码如下:  public static int Count(string cityName)
 {
 string cmdText = "";
 SqlConnection conn = new SqlConnection(DBH.DBA);
 SqlCommand cmd = null;
 cmdText = "Select count(*) From [Drugstore] Where CityName=@cityName ";
 cmd = new SqlCommand(cmdText, conn);
 cmd.Parameters.AddWithValue("@cityName", cityName);
 conn.Open();
 int total = (int)cmd.ExecuteScalar();
 conn.Close();
 return total;
 }
 
 刚开始全部函数调用是这样一个个写出来的,后来熟悉了 用SqlHelp方便好多,在后来就直接用动软.net代码生成器了,发现对原先的这些越来越陌生了 ,现在大致整理一下,和上面重复的代码部分省略。
 1. 添加数据
 
 复制代码 代码如下:  DrugstoreInfo info = new DrugstoreInfo();
 cmd.Parameters.AddWithValue("@ID",info.ID);
 try
 {
 conn.Open();
 return cmd.ExecuteNonQuery();
 }
 catch
 {
 throw;
 }
 finally
 {
 conn.Close();
 }
 
 .dataset 数据分页
 
 复制代码 代码如下:  public static DataSet indexQuery(int pageIndex, int pageSize)
 {
 ..
 SqlDataAdapter da = new SqlDataAdapter(cmd);
 DataSet ds = new DataSet();
 da.Fill(ds, (pageIndex - 1) * pageSize, pageSize, "Table1");
 return ds;
 }
 
 . 获得最大值
 
 复制代码 代码如下:  public static int GetMax()
 {
 string cmdText = "select Max(Id) from Application ";
 ..
 try
 {
 conn.Open();
 Object obj = cmd.ExecuteScalar();
 if (obj == null || obj is DBNull)
 {
 return 1;
 }
 return (int)obj + 1;
 }
 catch
 {
 throw;
 }
 finally
 {
 conn.Close();
 }
 }
 
 . select 选择
 
 复制代码 代码如下:  public static ApplicationInfo Select(int id)
 {
 string cmdText = "select ID from Application where ID=@ID";
 SqlConnection conn = new SqlConnection(DBH.ConnString);
 SqlCommand cmd = new SqlCommand(cmdText, conn);
 ApplicationInfo info = new ApplicationInfo();
 cmd.Parameters.AddWithValue("@ID", id);
 conn.Open();
 using (IDataReader dr = cmd.ExecuteReader())
 {
 if (dr.Read())
 {
 info.ID = (int)dr["ID"];
 }
 dr.Close();
 }
 conn.Close();
 return info;
 }
 
 .delete 删除
 
 复制代码 代码如下:  public static int Del(int id)
 {
 string cmdText = "Delete from Application Where ID= @ID";
 SqlConnection conn = new SqlConnection(DBH.ConnString);
 SqlCommand cmd = new SqlCommand(cmdText, conn);
 cmd.Parameters.AddWithValue("@ID", id);
 conn.Open();
 return cmd.ExecuteNonQuery();
 conn.Close();
 }
 
 . update 修改
 
 复制代码 代码如下:  public static int Update(ApplicationInfo info)
 {
 string cmdText = "Update Application Set City=@city Where ID=@ID";
 SqlConnection conn = new SqlConnection(DBH.ConnString);
 SqlCommand cmd = new SqlCommand(cmdText, conn);
 cmd.Parameters.AddWithValue("@ID", info.ID);
 try
 {
 conn.Open();
 return cmd.ExecuteNonQuery();
 }
 catch
 {
 throw;
 }
 finally
 {
 conn.Close();
 }
 }
 
 .配置
 
 复制代码 代码如下:  public class DBH
 {
 private DBH() { }
 private static readonly string _DBA = ConfigurationManager.ConnectionStrings["DBA"].ConnectionString;
 public static string DBA
 {
 get { return _DBA; }
 }
 }
 
 附: configurationManager 需要命名空间 using System.Configuration 和添加引用System.Configuration 双重操作。
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