我已经在这个主题上工作了4个小时，但我无法得到任何解决方案。
我的问题其实是; 我有5个表，我想创建一个控制器来创建不同的表。
我目前的代码如下，但此代码只创建一个表格。
public interface ISQLite
{
SQLiteConnection GetConnection();
}
-
public class TodoItem
{
public TodoItem ()
{
}
[PrimaryKey, AutoIncrement]
public int ID { get; set; }
public string Name { get; set; }
public string Notes { get; set; }
public bool Done { get; set; }
}
-
public class TodoItemDatabase
{
static object locker = new object ();
SQLiteConnection database;
/// <summary>
/// Initializes a new instance of the <see cref="Tasky.DL.TaskDatabase"/> TaskDatabase.
/// if the database doesn't exist, it will create the database and all the tables.
/// </summary>
/// <param name='path'>
/// Path.
/// </param>
public TodoItemDatabase()
{
database = DependencyService.Get<ISQLite> ().GetConnection ();
// create the tables
database.CreateTable<TodoItem>();
}
public IEnumerable<TodoItem> GetItems ()
{
lock (locker) {
return (from i in database.Table<TodoItem>() select i).ToList();
}
}
public IEnumerable<TodoItem> GetItemsNotDone ()
{
lock (locker) {
return database.Query<TodoItem>("SELECT * FROM [TodoItem] WHERE [Done] = 0");
}
}
public TodoItem GetItem (int id)
{
lock (locker) {
return database.Table<TodoItem>().FirstOrDefault(x => x.ID == id);
}
}
public int SaveItem (TodoItem item)
{
lock (locker) {
if (item.ID != 0) {
database.Update(item);
return item.ID;
} else {
return database.Insert(item);
}
}
}
public int DeleteItem(int id)
{
lock (locker) {
return database.Delete<TodoItem>(id);
}
}
}
-
public class SQLite_Android : ISQLite
{
public SQLite_Android()
{
}
#region ISQLite implementation
public SQLite.SQLiteConnection GetConnection()
{
var sqliteFilename = "TodoSQLite.db3";
string documentsPath = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal); // Documents folder
var path = Path.Combine(documentsPath, sqliteFilename);
// This is where we copy in the prepopulated database
Console.WriteLine(path);
if (!File.Exists(path))
{
var s = Forms.Context.Resources.OpenRawResource(Resource.Raw.TodoSQLite); // RESOURCE NAME ###
// create a write stream
FileStream writeStream = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write);
// write to the stream
ReadWriteStream(s, writeStream);
}
var conn = new SQLite.SQLiteConnection(path);
// Return the database connection
return conn;
}
#endregion
/// <summary>
/// helper method to get the database out of /raw/ and into the user filesystem
/// </summary>
void ReadWriteStream(Stream readStream, Stream writeStream)
{
int Length = 256;
Byte[] buffer = new Byte[Length];
int bytesRead = readStream.Read(buffer, 0, Length);
// write the required bytes
while (bytesRead > 0)
{
writeStream.Write(buffer, 0, bytesRead);
bytesRead = readStream.Read(buffer, 0, Length);
}
readStream.Close();
writeStream.Close();
}
}
---如何在一个控制器中创建多个表？
答案 0 :(得分：1)
看起来你正在使用Sqlite.net-pcl，对吧？
不支持来自同一型号的多个表（仅适用于简单的情况）。
您可以创建多个模型（可能只是继承），然后为每个模型调用CreatTable<T>。
答案 1 :(得分：1)
我解决了问题。也许这个解决方案有助于某些人。
我有两个DbHepler Class和两个用于在DB上创建两个表的模型类。
基本连接代码相同;
public interface ISQLite
{
SQLiteConnection GetConnection();
}
这是App.cs文件;
public class App : Application {
public App()
{
authenticationDB = new AuthenticationDbHelper(Database);
settingsDbHelper = new SettingsDbHelper(Database);
MainPage = new Views.MainMenuPage();
}
public static CreateDB Database
{
get
{
if (database == null)
{
database = new CreateDB();
}
return database;
}
}
}
CreateDB类是为所有表创建一个数据库所必需的
public class CreateDB
{
public SQLiteConnection database;
public object locker = new object();
public CreateDB()
{
database = DependencyService.Get<ISQLite>().GetConnection();
}
}
此接口是创建的表操作所必需的。自从实现这个类以来我们可以使用theese方法所有表。（T是表类）（要了解一下AuthenticationDBHelper类）
public interface SQLiteBase<T>
{
IEnumerable<T> GetItems();
T GetItem(long id);
long SaveItem(T item);
void UpdateItem(T item);
int DeleteItem(int id);
int Clear();
int getCount();
}
此DbHelper类将用于删除，插入，清除....项目。
public class AuthenticationDbHelper : SQLiteBase<AuthenticationDbTable>
{
SQLiteConnection database;
object locker;
public AuthenticationDbHelper(CreateDB db)
{
database = db.database;
locker = db.locker;
database.CreateTable<AuthenticationDbTable>();
}
public int Clear()
{
lock(locker)
{
return database.DeleteAll<AuthenticationDbTable>();
}
}
public int DeleteItem(int id)
{
lock (locker)
{
return database.Delete<AuthenticationDbTable>(id);
}
}
public AuthenticationDbTable GetItem(long id)
{
lock (locker)
{
return database.Table<AuthenticationDbTable>().FirstOrDefault(x => x.UserId == id);
}
}
public IEnumerable<AuthenticationDbTable> GetItems()
{
lock (locker)
{
return (from i in database.Table<AuthenticationDbTable>() select i).ToList();
}
}
public long SaveItem(AuthenticationDbTable item)
{
lock (locker)
{
return database.Insert(item);
}
}
public void UpdateItem(AuthenticationDbTable item)
{
lock(locker)
{
database.Update(item);
}
}
public int getCount()
{
return GetItems().Count();
}
}
我知道这很困惑，但这是最后一次。我们将创建用于身份验证的模型。
public class AuthenticationDbTable
{
public AuthenticationDbTable(long userId, string sessionId, string username, string clientuuid)
{
this.userId = userId;
this.sessionId = sessionId;
this.username = username;
this.clientuuid = clientuuid;
}
private long userId;
private string sessionId;
private string username;
private string clientuuid;
[PrimaryKey]
public long UserId
{
get { return userId; }
set { userId = value; }
}
public string SessionId
{
get { return sessionId; }
set { sessionId = value; }
}
public string Username
{
get { return username; }
set { username = value; }
}
public string Clientuuid
{
get { return clientuuid; }
set { clientuuid = value; }
}
}
是
AuthenticationDbTable authentication = new AuthenticationDbTable(authenticateduser.User.UserId, r.Retval.SessionStatus.SessionId, authenticateduser.User.Name, authenticateduser.Clientuuid);
App.authenticationDB.SaveItem(authentiaction);
注意
要创建第二个表，您可以使用相同的方法。您应该创建第二个DbHelper和模型类。假设您将为设置创建一个表。您应该创建SettingsDbHelper和SettingsDbTable类。通过相同的方式。
谢谢：）