4《數(shù)據(jù)庫原理及應(yīng)用技術(shù)》課程指導(dǎo)平臺功能模塊具體實(shí)現(xiàn)

4.1 用戶登錄認(rèn)證部分代碼

//?數(shù)據(jù)庫連接操作幫助類

public?sealed?class?SqlHelper

{

//?執(zhí)行數(shù)據(jù)庫讀取

public?static?SqlDataReaderExecuteReader(string?connectionString,CommandType?commandType,?stringcommandText)

{

return?ExecuteReader(connectionString, commandType,commandText, (SqlParameter[])null);

?}

//?執(zhí)行數(shù)據(jù)庫讀取

public?static?SqlDataReaderExecuteReader(string?connectionString,CommandType?commandType,?stringcommandText,?paramsSqlParameter[]commandParameters)

{

????if?(connectionString ==?null?|| connectionString.Length == 0)?throw?newArgumentNullException("connectionString");

????????????SqlConnection?connection =?null;

???????? ???try

??????????? {

//?新建一個(gè)數(shù)據(jù)庫連接實(shí)例

connection =?newSqlConnection(connectionString);

//?建立連接

????????????????connection.Open();

????????????????returnExecuteReader(connection,null, commandType,commandText, commandParameters,SqlConnectionOwnership.Internal);

??????????? }

????????????catch

??????????? {

????????????????if?(connection !=?null)

//?關(guān)閉數(shù)據(jù)庫連接

connection.Close();

???? ??throw;

??? ??}

}

}

//?驗(yàn)證用戶登錄類

public?class?CheckUserLogin{

???????SqlConnection?conn;

????????public?CheckUserLogin()

?? ?????{

//讀取web.config里面的數(shù)據(jù)庫連接字串并new一個(gè)SqlConnection實(shí)例

????????????conn =

new

SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["ConnStr"].ToString());

??????? }

//取得用戶密碼

???????public?string?getPassword(string?user_no,?stringrole)

?????? {

???????????string?password =?String.Empty;

???????????SqlDataReader?dr =?null;

???????????if?(role ==?"stu")

?????????? {

?????????????? dr =?SqlHelper.ExecuteReader(conn,CommandType.Text,?"select passwordfrom DB_STU where stu_id ="?+ user_no);

??????????}

??????????…………………………..

???????????return?password; }

}

4.2 學(xué)生作業(yè)修改功能部分代碼