出现SQLite异常并显示消息：没有这样的表

问题描述：

我创建了一个从计算机收集信息（计算机名称，CPU，内存等）的应用程序，但是我很难显示存储在SQLite数据库中的信息，当我执行查询时，我得到否当我确定知道我有一个称为硬件的表时，出现 SUCH TABLE消息？

I created an application that collects information from the computer (computer name, CPU, Memory, etc) but I am having such a hard time displaying the information stored in the SQLite database, when I execute a query I get the "NO SUCH TABLE" message when I know for sure I have a table called "hardware" what am I doing wrong?

这里是我用来执行查询的代码：

Here the code I use to execute the query:

procedure TMain.executeButtonClick(Sender: TObject);
var
  results: TDataSet;
  query: String;

begin
  outputMemo.ClearSelection;
  query := 'SELECT * FROM hardware;';
  try
    SQLConnection1.Execute(query, nil, results);
  except
    on E: Exception do
      outputMemo.Text := 'Exception raised with message: ' + E.Message;
  end;
  ShowSelectResults(results);
end;

每次运行应用程序时，都会以编程方式创建数据库文件和表

The database file and table are created programmatically created every time the application runs

procedure CheckForDatabase;
var
  sldb: TSQLiteDatabase;
  sSQL: string;

begin
  slDBPath := ExtractFilePath(paramstr(0)) + 'ComputerName.db';
  // ShowMessage(slDBPath);
  sldb := TSQLiteDatabase.Create(slDBPath);
  try
    if sldb.TableExists('hardware') then
      begin
        sSQL := 'DROP TABLE hardware';
        sldb.ExecSQL(sSQL);
      end;

    sSQL := 'CREATE TABLE hardware (id INTEGER PRIMARY KEY, compname TEXT, username TEXT, model TEXT, manufacturer TEXT, domain TEXT, ip TEXT, serialnumber TEXT)';
    sldb.ExecSQL(sSQL);
    sldb.ExecSQL('CREATE INDEX sHardware ON hardware(CompName);');
    sldb.BeginTransaction;
    sSQL := 'INSERT INTO hardware(id, compname, username, model, manufacturer, domain, ip, serialnumber) VALUES (1, "AMD8537", "OMonge", "Gigabyte", "Gigabyte", "Workgroup", "192.168.1.11", "8746652");';
    sldb.ExecSQL(sSQL);
    sldb.Commit;
  finally
    sldb.Free;
  end;
end;

这是SQLite数据库：

And this is the SQLite database:

可以提供任何帮助提供给我将不胜感激。谢谢。

Any help you can provide me with will be greatly appreciated. Thank you.

答

您标记了Delphi-XE2，所以我的答案属于XE2

You Taged Delphi-XE2 so my answer belongs to XE2

从RAD Studio XE3版本开始，TSQLMonitor支持SQLite数据库。 ...

From version RAD Studio XE3 TSQLMonitor supports SQLite databases. ...

使用XE2不能将 SQLConnection1：TSQLConnection; 与驱动程序 Sqlite一起使用！

将不起作用 SQLConnection1.Execute（query，nil，results）;

With XE2 You can not use SQLConnection1: TSQLConnection; with Driver Sqlite !
Will not work SQLConnection1.Execute(query, nil, results);

根据所使用的代码，它似乎是用于Sqlite 3的简单Delphi包装器。$ c>起作用。

According to the code used , it seems to be the simple Delphi wrapper for Sqlite 3 to act.

因此您可以使用刚刚创建的 sldb 。

So you can use the just created sldb .

slDBPath := ExtractFilePath(paramstr(0)) + 'ComputerName.db';
sldb := TSQLiteDatabase.Create(slDBPath);

在程序CheckForDatabase中;

删除

var
  sldb: TSQLiteDatabase;

并将其放置到应用程序的界面

and put it to the interface of your Application

private
    { Private declarations }
    sltb: TSQLIteTable;
    sldb: TSQLiteDatabase;

还删除 sldb.Free; 最终阻止

finally
    sldb.Free;
end;

在您的 executeButtonClick（...

procedure TMain.executeButtonClick(Sender: TObject);
var
  query: String;

begin
  outputMemo.ClearSelection;
  query := 'SELECT * FROM hardware;';
  sltb := sldb.GetTable(query);
  if sltb.Count > 0 then begin
     //display first row
     ....
  if not sltb.IsLastRow the begin
     sltb.Next;
     //display next row
     ....

如何显示字段值：在这里

出现SQLite异常并显示消息：没有这样的表

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