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ADO.NET 数据连接查询

IT知识数据连接连接查询ADO.NET

我自横刀向天笑，去留肝胆两昆仑。这篇文章主要讲述ADO.NET 数据连接查询相关的知识，希望能为你提供帮助。


static stringsqlcon = "server=.; database=; Integrated Security=true; ";
/// < summary>
/// 新增数据
/// < /summary>
public static void Add()

【ADO.NET 数据连接查询】//string sqlcon = "server=.; database=; Integrated Security=true; ";
SqlConnection conn=new SqlConnection(sqlcon);
string sqlStr="insert into Boook(b_id,b_title,b_author,b_money)values(1,ASP.NET，莫言,100)";
SqlCommand cmd=new SqlCommand(sqlStr,conn);
conn.Open();
int i = cmd.ExecuteNonQuery();
conn.Close();
if (i> 0)

Console.Write("新增成功！");

else

Console.Write("新增失败！");


/// < summary>
/// 删除数据
/// < /summary>
public static void Delete()

//string sqlcon = "server=.; database=; Integrated Security=true; ";
SqlConnection conn = new SqlConnection(sqlcon);
string sqlStr = "delete from book where b_id=1";
SqlCommand cmd = new SqlCommand(sqlStr,conn);
conn.Open();
int i = cmd.ExecuteNonQuery();
conn.Close();
if (i > 0)

Console.Write("删除成功！");

else

Console.Write("删除失败！");


/// < summary>
/// 数据更新，软删除
/// < /summary>
private static void Update()

//string sqlcon = "server=.; database=; Integrated Security=true; ";
SqlConnection conn = new SqlConnection(sqlcon);
string sqlStr = "update Boook set b_id =2 where b_id=1";
SqlCommand cmd = new SqlCommand(sqlStr, conn);
conn.Open();
int i = cmd.ExecuteNonQuery();
conn.Close();
if (i > 0)

Console.Write("更新成功！");

else

Console.Write("更新失败！");


/// < summary>
/// 读取单个值
/// < /summary>
private static void selectSingle()

SqlConnection conn = new SqlConnection(sqlcon);
string sqlStr = "select * from Book";
SqlCommand cmd = new SqlCommand(sqlStr, conn);
conn.Open();
object obj = cmd.ExecuteScalar();
conn.Close();
Console.Write(obj.ToString());

/// < summary>
/// dateReader读取数据，逐行读取，通过下表访问列
/// < /summary>
private static void dateReader()

SqlConnection conn = new SqlConnection(sqlcon);
string sqlStr = "select * from Book";
SqlCommand cmd = new SqlCommand(sqlStr, conn);
conn.Open();
SqlDataReader dr = cmd.ExecuteReader();
if (dr.HasRows)

while (dr.Read())//如果读到下一行数据就返回True，且本身就属于那一行数据

Console.Write(dr[0].ToString() + _ + dr[1].ToString()+_+dr["ID"].ToString());


else

Console.Write("无数据");

dr.Close();
conn.Close();

//使用适配器填充数据集SqlDataAdapter不需要手动开关，它能够自己开关
public static void QueryListAdapter()

SqlConnection con = new SqlConnection(sqlcon);
string sqlStr = "select*from book";
SqlDataAdapter da = new SqlDataAdapter(sqlStr,con);
DataSet ds = new DataSet();
da.Fill(ds);
DataTable dt = ds.Tables[0];
//循环数据表中的每一行
for (int i = 0; i < dt.Rows.Count; i++)

DataRow dr = dt.Rows[i]; //将表中的一行拿出来给行对象
Console.WriteLine(dr[0].ToString() + "_" + dr["ID"].ToString());


//使用适配器填充数据集SqlDataAdapter不需要手动开关，它能够自己开关
public static void QueryListAdapter2()

SqlConnection con = new SqlConnection(sqlcon);
string sqlStr = "select*from book";
SqlDataAdapter da = new SqlDataAdapter(sqlStr, con);
DataSet ds = new DataSet();
da.Fill(ds);
DataTable dt = ds.Tables[0];
//循环数据表中的每一行
for (int i = 0; i < dt.Rows.Count; i++)

DataRow dr = dt.Rows[i]; //将表中的一行拿出来给行对象
Console.WriteLine(dr[0].ToString() + "_" + dr["ID"].ToString());


//调用存储过程查询数据
public static void QuerListByProc()

SqlConnection conn = new SqlConnection(sqlcon);
SqlCommand cmd=new SqlCommand("usp_GetBookMyCateId",conn);
//无参数的存储过程
SqlParameter sp2 = new SqlParameter();
sp2.ParameterName = "@cateId";
sp2.SqlDbType = SqlDbType.Int;
sp2.Value = https://www.songbingjia.com/android/2;
cmd.Parameters.Add(sp2);
//有两个参数的存储过程
SqlParameter sp = new SqlParameter("@cateId", 2);
cmd.Parameters.Add(sp);
SqlDataAdapter da = new SqlDataAdapter();
DataTable dt = new DataTable();
da.Fill(dt);
foreach(DataRow dr in dt.Rows)

Console.WriteLine(dr[0].ToString() + "_" + dr["ID"].ToString());


//调用多个参数的存储过程查询
private static void QueryListByProc2()

SqlConnection conn = new SqlConnection(sqlcon);
SqlCommand cmd = new SqlCommand("proGetPageData", conn);
cmd.CommandType = CommandType.StoredProcedure;
//尽量不要使用两个参数的存储过程，类型是枚举类型，另外一个两个参数的函数值混淆
//SqlParameter par = new SqlParameter("@Id", DbType.Int32);
//SqlParameter par = new SqlParameter("@id", 11);
//赋值多个参数
SqlParameter[] paras =
new SqlParameter("@pageIndex",SqlDbType.Int,4),//这里的4是代表整型的长度
new SqlParameter("@pageSize",SqlDbType.Int,4)
;
//cmd.Parameters.AddRange(paras);
paras[0].Value = https://www.songbingjia.com/android/1; //搜索第一页
paras[1].Value = https://www.songbingjia.com/android/2; //赋值的
cmd.Parameters.AddRange(paras); //为command对象添加pameters数组
conn.Open();
//SqlDataReader dr = cmd.ExecuteReader();
//while (dr.Read())
//
//Console.Write("id=" + dr[0].ToString());
//
//dr.Close();
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
foreach (DataRow dr in dt.Rows)

Console.WriteLine(dr[0].ToString() + "_" + dr[1].ToString());

conn.Close();

//调用带输出参数的存数过程
private static void QuerListProc3()

SqlConnection conn = new SqlConnection(sqlcon);
SqlCommand cmd = new SqlCommand("proGetData2", conn);
SqlParameter[] paras =
new SqlParameter("@pageIndex",SqlDbType.Int),
new SqlParameter("@pageSize",SqlDbType.Int),
new SqlParameter("@pageCount",SqlDbType.Int),
new SqlParameter("@rowCount",SqlDbType.Int)
;
paras[0].Value = https://www.songbingjia.com/android/1;
paras[1].Value = https://www.songbingjia.com/android/2;
paras[2].Direction = ParameterDirection.Output;
paras[3].Direction = ParameterDirection.Output; //设置参数的输出方向
cmd.Parameters.AddRange(paras);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
foreach (DataRow dr in dt.Rows)

Console.WriteLine(dr[0].ToString() + "_" + dr[1].ToString());

int pageCount=Convert.ToInt32(cmd.Parameters[2].Value);
int rowCount=Convert.ToInt32(cmd.Parameters[3].Value); //获取输出参数
Console.WriteLine("pageCount=" + pageCount + ",rowCount=" + rowCount);








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