SqlConnection,SqlCommand,SqldataReader的用法总结

本文提供了使用SqlConnection、SqlCommand和SqlDataReader进行数据库操作的详细示例。通过这些示例,读者可以了解到如何建立数据库连接、执行SQL查询并获取结果集,最终将数据绑定到GridView控件上。

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SqlConnection,SqlCommand,SqldataReader的用法总结:

希望对新手有所帮助!!! 

 

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page 
{
    
protected void Page_Load(object sender, EventArgs e)
    {
        
//-------------------SqlConnection,SqlCommand,SqldataReader的用法-------------------//

        
//下面的4种形式等价,如果你的数据库是Windows连接方法,直接把连接字符串改成"server=.;database=northwind;integrated security=true;"
        
//如果你的数据库是某个实例名,直接把"server=."改成"server=你的计算机名实例名"就可以了

        SqlConnection con 
= new SqlConnection();
        con.ConnectionString 
= "server=.;database=northwind;uid=sa;pwd=;";  //双引号中的最后一个分号可以去掉
        con.Open();
        SqlCommand cmd 
= con.CreateCommand();
        cmd.CommandText 
= "select * from customers";
        SqlDataReader sdr 
= cmd.ExecuteReader();
        
this.GridView1.DataSource = sdr;
        
this.GridView1.DataBind();
        sdr.Close();
        con.Close();

        
//SqlConnection con = new SqlConnection();
        
//con.ConnectionString = "server=.;database=northwind;uid=sa;pwd=;";   //双引号中的最后一个分号可以去掉
        
//con.Open();
        
//SqlCommand cmd = new SqlCommand("select * from customers");
        
//cmd.Connection = con;
        
//SqlDataReader sdr = cmd.ExecuteReader();
        
//this.GridView1.DataSource = sdr;
        
//this.GridView1.DataBind();
        
//sdr.Close();
        
//con.Close();


        
////我最经常用这一种,同时连接对象是整个程序的公共对象,所以我一般会把数据库连接封装到一个类中,这样就可以在程序的任何地方随时调用
        //SqlConnection con = new SqlConnection("server=.;database=northwind;uid=sa;pwd=;"); //双引号中的最后一个分号可以去掉
        
//con.Open();
        
//SqlCommand cmd = new SqlCommand("select * from customers", con);
        
//SqlDataReader sdr = cmd.ExecuteReader();
        
//this.GridView1.DataSource = sdr;
        
//this.GridView1.DataBind();
        
//sdr.Close();
        
//con.Close();

        
//SqlConnection con = new SqlConnection();
        
//con.ConnectionString = "server=.;database=northwind;uid=sa;pwd=;";   //双引号中的最后一个分号可以去掉
        
//con.Open();
        
//SqlCommand cmd = new SqlCommand();
        
//cmd.Connection = con;
        
//cmd.CommandText = "select * from customers";
        
//cmd.CommandType = CommandType.Text;  //这条语句是多余的,因为默认就是Text 
        
//SqlDataReader sdr = cmd.ExecuteReader();
        
//this.GridView1.DataSource = sdr;
        
//this.GridView1.DataBind();
        
//sdr.Close();
        
//con.Close();
}

以上四种方法都可以把数据库中的数据读出来,绑定到GridView控件!!!

using System; using System.Collections; using System.Data; using System.Data.SqlClient; namespace RxjhServer.DbClss { public class DBA { public static void serlog(string txt) { string sqlJl = World.SqlJl; if (sqlJl.Length == 0) { return; } string text = sqlJl; char[] separator = new char[1] { '|' }; string[] array = text.Split(separator); string[] array2 = array; string[] array3 = array2; foreach (string text2 in array3) { if (txt.ToLower().IndexOf(text2.ToLower()) != -1) { Form1.WriteLine(99, txt); } } } public static void serlog(string txt, SqlParameter[] prams) { string sqlJl = World.SqlJl; if (sqlJl.Length == 0) { return; } string[] array = sqlJl.Split('|'); for (int i = 0; i < array.Length; i++) { if (txt.ToLower().IndexOf(array[i].ToLower()) != -1) { Form1.WriteLine(99, txt); } } for (int j = 0; j < array.Length; j++) { foreach (SqlParameter sqlParameter in prams) { if (sqlParameter.SqlValue.ToString().ToLower().IndexOf(array[j].ToLower()) != -1) { Form1.WriteLine(99, txt + " " + sqlParameter.SqlValue.ToString()); } } } } public static void Setlog(string txt, SqlParameter[] prams, Exception ex) { Form1.WriteLine(100, "-----------DBA数据层_错误-----------"); Form1.WriteLine(100, txt); if (prams != null) { foreach (SqlParameter sqlParameter in prams) { Form1.WriteLine(100, sqlParameter.SqlValue.ToString()); } } Form1.WriteLine(100, ex.Message); } public static string getstrConnection(string db) { try { if (db == null) { db = "GameServer"; } World.sql = (World.Db.TryGetValue(db, out var value) ? value.SqlConnect : null); DbClass value2; return World.Db.TryGetValue(db, out value2) ? value2.SqlConnect : null; } catch { return null; } } public static int ExeSqlCommand(string sqlCommand, SqlParameter[] prams) { serlog(sqlCommand, prams); using SqlConnection sqlConnection = new SqlConnection(getstrConnection(null)); using SqlCommand sqlCommand2 = SqlDBA.CreateCommandSql(sqlConnection, sqlCommand, prams); int result = -1; try { sqlConnection.Open(); } catch { return -1; } try { result = sqlCommand2.ExecuteNonQuery(); } catch (Exception ex) { Setlog(sqlCommand, prams, ex); } sqlCommand2.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return result; } public static int ExeSqlCommand(string sqlCommand, SqlParameter[] prams, string server) { serlog(sqlCommand, prams); using SqlConnection sqlConnection = new SqlConnection(getstrConnection(server)); using SqlCommand sqlCommand2 = SqlDBA.CreateCommandSql(sqlConnection, sqlCommand, prams); int result = -1; try { sqlConnection.Open(); } catch { return -1; } try { result = sqlCommand2.ExecuteNonQuery(); } catch (Exception ex) { Setlog(sqlCommand, prams, ex); } sqlCommand2.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return result; } public static int ExeSqlCommand(string sqlCommand) { serlog(sqlCommand); using SqlConnection sqlConnection = new SqlConnection(getstrConnection(null)); using SqlCommand sqlCommand2 = new SqlCommand(sqlCommand, sqlConnection); int result = -1; try { sqlConnection.Open(); } catch { return -1; } try { result = sqlCommand2.ExecuteNonQuery(); } catch (Exception ex) { Setlog(sqlCommand, null, ex); } sqlCommand2.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return result; } public static int ExeSqlCommand(string sqlCommand, string server) { serlog(sqlCommand); using SqlConnection sqlConnection = new SqlConnection(getstrConnection(server)); using SqlCommand sqlCommand2 = new SqlCommand(sqlCommand, sqlConnection); int result = -1; try { sqlConnection.Open(); } catch { return -1; } try { result = sqlCommand2.ExecuteNonQuery(); } catch (Exception ex) { Setlog(sqlCommand, null, ex); } sqlCommand2.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return result; } public static int ExeSqlCommand(string sqlCommand, ref Exception exception, string db) { serlog(sqlCommand); using SqlConnection sqlConnection = new SqlConnection(getstrConnection(null)); using SqlCommand sqlCommand2 = new SqlCommand(sqlCommand, sqlConnection); try { sqlConnection.Open(); } catch (Exception ex) { Exception ex2 = (exception = ex); return -1; } int result = sqlCommand2.ExecuteNonQuery(); sqlCommand2.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return result; } public static DataTable GetDBToDataTable(string sqlCommand, SqlParameter[] prams) { serlog(sqlCommand, prams); using SqlConnection sqlConnection = new SqlConnection(getstrConnection(null)); using SqlDataAdapter sqlDataAdapter = new SqlDataAdapter(); SqlCommand sqlCommand5 = (sqlDataAdapter.SelectCommand = SqlDBA.CreateCommandSql(sqlConnection, sqlCommand, prams)); SqlCommand sqlCommand2 = sqlCommand5; SqlCommand sqlCommand3 = sqlCommand2; using (sqlCommand3) { try { sqlConnection.Open(); } catch (Exception ex) { Form1.WriteLine(100, "DBA数据层_错误" + ex.Message + " " + sqlCommand); return null; } DataTable dataTable = new DataTable(); try { sqlDataAdapter.Fill(dataTable); } catch (Exception ex2) { Setlog(sqlCommand, prams, ex2); } sqlDataAdapter.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return dataTable; } } public static DataTable GetDBToDataTable(string sqlCommand, SqlParameter[] prams, string server) { serlog(sqlCommand, prams); using SqlConnection sqlConnection = new SqlConnection(getstrConnection(server)); using SqlDataAdapter sqlDataAdapter = new SqlDataAdapter(); SqlCommand sqlCommand5 = (sqlDataAdapter.SelectCommand = SqlDBA.CreateCommandSql(sqlConnection, sqlCommand, prams)); SqlCommand sqlCommand2 = sqlCommand5; SqlCommand sqlCommand3 = sqlCommand2; using (sqlCommand3) { try { sqlConnection.Open(); } catch (Exception ex) { Form1.WriteLine(100, "DBA数据层_错误" + ex.Message + " " + sqlCommand); return null; } DataTable dataTable = new DataTable(); try { sqlDataAdapter.Fill(dataTable); } catch (Exception ex2) { Setlog(sqlCommand, prams, ex2); } sqlDataAdapter.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return dataTable; } } public static DataTable GetDBToDataTable(string sqlCommand) { serlog(sqlCommand); using SqlConnection sqlConnection = new SqlConnection(getstrConnection(null)); using SqlDataAdapter sqlDataAdapter = new SqlDataAdapter(); SqlCommand sqlCommand5 = (sqlDataAdapter.SelectCommand = new SqlCommand(sqlCommand, sqlConnection)); SqlCommand sqlCommand2 = sqlCommand5; SqlCommand sqlCommand3 = sqlCommand2; using (sqlCommand3) { try { sqlConnection.Open(); } catch (Exception ex) { Form1.WriteLine(100, "DBA数据层_错误" + ex.Message + " " + sqlCommand); return null; } DataTable dataTable = new DataTable(); try { sqlDataAdapter.Fill(dataTable); } catch (Exception ex2) { Setlog(sqlCommand, null, ex2); } sqlDataAdapter.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return dataTable; } } public static DataTable GetDBToDataTable(string sqlCommand, string server) { serlog(sqlCommand); using SqlConnection sqlConnection = new SqlConnection(getstrConnection(server)); using SqlDataAdapter sqlDataAdapter = new SqlDataAdapter(); SqlCommand sqlCommand5 = (sqlDataAdapter.SelectCommand = new SqlCommand(sqlCommand, sqlConnection)); SqlCommand sqlCommand2 = sqlCommand5; SqlCommand sqlCommand3 = sqlCommand2; using (sqlCommand3) { try { sqlConnection.Open(); } catch { return null; } DataTable dataTable = new DataTable(); try { sqlDataAdapter.Fill(dataTable); } catch (Exception ex) { Setlog(sqlCommand, null, ex); } sqlDataAdapter.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return dataTable; } } public static DataRowCollection GetDBValue(string sqlCommand, string db) { return GetDBToDataTable(sqlCommand).Rows; } public static ArrayList GetDBValue_1(string sqlCommand, string db) { serlog(sqlCommand); using SqlConnection sqlConnection = new SqlConnection(getstrConnection(null)); using SqlCommand sqlCommand2 = new SqlCommand(sqlCommand, sqlConnection); try { sqlConnection.Open(); } catch { return null; } SqlDataReader sqlDataReader = sqlCommand2.ExecuteReader(); if (!sqlDataReader.HasRows) { sqlDataReader.Close(); sqlDataReader.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return null; } ArrayList arrayList = new ArrayList(); if (sqlDataReader.Read()) { for (int i = 0; i < sqlDataReader.FieldCount; i++) { arrayList.Add(sqlDataReader[i]); } } sqlDataReader.Close(); sqlDataReader.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); sqlCommand2.Dispose(); return arrayList; } public static ArrayList GetDBValue_2(string sqlCommand, string db) { serlog(sqlCommand); using SqlConnection sqlConnection = new SqlConnection(getstrConnection(null)); using SqlCommand sqlCommand2 = new SqlCommand(sqlCommand, sqlConnection); try { sqlConnection.Open(); } catch { return null; } SqlDataReader sqlDataReader = sqlCommand2.ExecuteReader(); if (!sqlDataReader.HasRows) { sqlDataReader.Close(); sqlDataReader.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return null; } ArrayList arrayList = new ArrayList(); while (sqlDataReader.Read()) { arrayList.Add(sqlDataReader[0]); } sqlDataReader.Close(); sqlDataReader.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); sqlCommand2.Dispose(); return arrayList; } public static object GetDBValue_3(string sqlCommand) { serlog(sqlCommand); object result = null; using SqlConnection sqlConnection = new SqlConnection(getstrConnection(null)); using SqlCommand sqlCommand2 = new SqlCommand(sqlCommand, sqlConnection); try { sqlConnection.Open(); } catch { return null; } try { result = sqlCommand2.ExecuteScalar(); } catch (Exception ex) { Form1.WriteLine(100, "DBA数据层_错误" + ex.Message + " " + sqlCommand); } sqlCommand2.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return result; } public static object GetDBValue_3(string sqlCommand, SqlParameter[] prams) { serlog(sqlCommand, prams); object result = null; using SqlConnection sqlConnection = new SqlConnection(getstrConnection(null)); using SqlCommand sqlCommand2 = SqlDBA.CreateCommandSql(sqlConnection, sqlCommand, prams); try { sqlConnection.Open(); } catch { return null; } try { result = sqlCommand2.ExecuteScalar(); } catch (Exception ex) { Form1.WriteLine(100, "DBA数据层_错误" + ex.Message + " " + sqlCommand); } sqlCommand2.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return result; } public static object GetDBValue_3(string sqlCommand, string db) { serlog(sqlCommand); object result = null; using SqlConnection sqlConnection = new SqlConnection(getstrConnection(db)); using SqlCommand sqlCommand2 = new SqlCommand(sqlCommand, sqlConnection); try { sqlConnection.Open(); } catch { return null; } try { result = sqlCommand2.ExecuteScalar(); } catch (Exception ex) { Form1.WriteLine(100, "DBA数据层_错误" + ex.Message + " " + sqlCommand); } sqlCommand2.Dispose(); sqlConnection.Close(); sqlConnection.Dispose(); return result; } } } 这是我的DBA类
最新发布
07-19
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