Ⅰ 基於C#與sql開發的圖書管理系統(VS2010,SQL2008)
http://wenku..com/link?url=_KUiS6VLQtrY9IaDCXoIt_gpaLq9Yz-pyF31p490dmIyxwKGYKZfdcS
Ⅱ sql多表聯合查詢 數據不正確。
SELECTc.phone,d.y,b.b_f,b.b_d
FROMA
LEFTJOINCONA.c_id=C.id
LEFTJOINBONC.id=B.c_id
LEFTJOINDONB.d_id=D.id
Ⅲ 在XPO中怎麼通過配置文件來讀取資料庫鏈接
xml version="1.0" encoding="utf-8"?><configuration> <appSettings> <add key="ServerType" value="Access" /> <add key="Server" value="" /> <add key="Database" value="E:data.mdb" /> <add key="User" value="" /> <add key="Password" value="" /> </appSettings></configuration>通過AppSettingReader類來獲取配置文件中的設置，然後組合一個連接字元串。我們建議你使用Provider類的GetConnectString方法來（在DevExpress.Xpo.DB命名空間）。using System.Configuration;
using DevExpress.Xpo;
private static string GetConnectionString() {
AppSettingsReader config = new AppSettingsReader();
string serverType, server, database, user, password;
serverType = ((string)(config.GetValue("ServerType", typeof(string))));
server = ((string)(config.GetValue("Server", typeof(string))));
database = ((string)(config.GetValue("Database", typeof(string))));
user = ((string)(config.GetValue("User", typeof(string))));
password = ((string)(config.GetValue("Password", typeof(string))));
switch(serverType) {
case "MSSQL":
return DevExpress.Xpo.DB.MSSqlConnectionProvider.GetConnectionString(server, user, password, database);
case "Access":
return DevExpress.Xpo.DB.AccessConnectionProvider.GetConnectionString(database, user, password);
// ... generate connection strings for other providers, e.g. MySql, Firebird, etc. default:
return Session.GetDefaultConnectionString();
}} 在應用程序的入口，連接字元串必須被賦值到DefaultSession對象。