在SQL server2000数据库中,连接 *** 作包含哪几个类别,试分别加以说明?

如果只是连接SQL

Server *** 作，一般就是使用

SQLConnection对象，如果要连接ACCESS或Excel

就以用到OLEDBConnection对象。如果是要对SQL

Server数据库增、删、改、查的 *** 作，就还要用到:

–

Command对象，用于执行SQL命令

–

AdapterData对象(数据适配器)

，是连接数据库与数据集的数据桥梁

–

DataSet

对象(数据集)，存放数据的内存区域

–

DataReader

对象(数据阅读器)

，用于执行Command命令后高速读取数据

做一个DBHelper类在，数据访问层中直接调用它

public class DBHelper

{

private static SqlConnection connection

public static SqlConnection Connection

{

get

{

string connectionString = "server=(local)\\db2005database=MyBookShopuid=sapwd=sasa"

//string connectionString = ConfigurationManager.ConnectionStrings["MyConstr"].ConnectionString

if (connection == null)

{

connection = new SqlConnection(connectionString)

connection.Open()

}

else if (connection.State == System.Data.ConnectionState.Closed)

{

connection.Open()

}

else if (connection.State == System.Data.ConnectionState.Broken)

{

connection.Close()

connection.Open()

}

return connection

}

}

public static int ExecuteCommand(string safeSql)

{

SqlCommand cmd = new SqlCommand(safeSql, Connection)

int result = cmd.ExecuteNonQuery()

return result

}

public static int GetScalar(string safeSql)

{

SqlCommand cmd = new SqlCommand(safeSql, Connection)

int result = Convert.ToInt32(cmd.ExecuteScalar())

return result

}

public static SqlDataReader GetReader(string safeSql)

{

SqlCommand cmd = new SqlCommand(safeSql, Connection)

SqlDataReader reader = cmd.ExecuteReader()

return reader

}

public static DataTable GetDataSet(string safeSql)

{

DataSet ds = new DataSet()

SqlCommand cmd = new SqlCommand(safeSql, Connection)

SqlDataAdapter da = new SqlDataAdapter(cmd)

da.Fill(ds)

return ds.Tables[0]

}

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