Question

我的代码引发了异常：

没有这样的表：Table_Name

我花了一整天时间试图解决它，但到目前为止没有成功。

我使用SQLite3.exe创建数据库，创建表person并插入数据。当我查询表person的内容时，它会向我显示正面结果。

不幸的是，当我使用此代码显示表内容时，会引发异常。

这是代码：

procedure TForm1.connectButtonClick(Sender: TObject);
begin
  // Set the path of your database file.
  // Replace "full_path_to_your_database_file" with the absolute path 
  // to your SQLite database file.
  SQLConnection1.Params.Add('Database=D:\testdb.db');
  try
    // Establish the connection.
    SQLConnection1.Connected := true;
    executeButton.Enabled := true;
    outputMemo.Text := 'Connection established!';
  except
    on E: EDatabaseError do
      ShowMessage('Exception raised with message' + E.Message);
  end;
end;

procedure TForm1.executeButtonClick(Sender: TObject);
var
  results: TDataSet;
  query: String;
begin
  outputMemo.Clear;
  // A random query
  query := 'SELECT * FROM person;';

  try
  // Execute the query on the database.
    SQLConnection1.Execute(query, nil, results);
  except
    on E: Exception do
      outputMemo.Text := 'Exception raised with message: ' + E.Message;
  end;
  // Show the results of the query in a TMemo control.
  ShowSelectResults(results);
end;

procedure TForm3.ShowSelectResults(results: TDataSet);
var
  names: TStringList;
  i: Integer;
  currentField: TField;
  currentLine: string;
begin
  if not results.IsEmpty then
  begin
    results.First;
    names := TStringList.Create;
    results.GetFieldNames(names);
    while not results.Eof do
    begin
      currentLine := '';
      for i := 0 to names.Count - 1 do
      begin
        currentField := results.FieldByName(names[i]);
        currentLine := currentLine + ' ' + currentField.AsString;
      end;
      outputMemo.Lines.Add(currentLine);
      results.Next;
    end;
  end;
end;

Answer 1

您的数据库和/或表是否已损坏，或者您的代码的某些部分出现了错误，但是您没有向我们展示。

以下代码创建并填充新表，在Delphi Seattle上完美运行并生成预期结果，即outputMemo中的一个数据行。

我建议你关闭＆amp;在尝试之前，重新启动Delphi并关闭可能使用与DB相同的Sqlite3.Dll的任何其他应用程序。

（我已将outputMemo和ShowSelectResults移至Form1）

procedure TForm1.executeButtonClick(Sender: TObject);
var
  results: TDataSet;
  query: String;
begin
  outputMemo.Clear;

  query := 'CREATE TABLE TESTTABLE (ID BIGINT, NAME NVARCHAR(80) )';
  SQLConnection1.Execute(query, nil, Nil);

  query := 'INSERT INTO TESTTABLE(ID, NAME) VALUES(1, ''One'')';
  SQLConnection1.Execute(query, nil, Nil);

  query := 'SELECT * FROM TESTTABLE';

  try
  // Execute the query on the database.
    SQLConnection1.Execute(query, nil, results);

  except
    on E: Exception do
      outputMemo.Text := 'Exception raised with message: ' + E.Message;
  end;
  // Show the results of the query in a TMemo control.
  ShowSelectResults(results);

  query := 'DROP TABLE TESTTABLE';
  SQLConnection1.Execute(query, nil, Nil);

end;

procedure TForm1.ShowSelectResults(results: TDataSet);
var
  names: TStringList;
  i: Integer;
  currentField: TField;
  currentLine: string;
begin
  if not results.IsEmpty then
  begin
    results.First;
    names := TStringList.Create;
    try
      results.GetFieldNames(names);
      while not results.Eof do
      begin
        currentLine := '';
        for i := 0 to names.Count - 1 do
        begin
          currentField := results.FieldByName(names[i]);
          currentLine := currentLine + ' ' + currentField.AsString;
        end;
        outputMemo.Lines.Add(currentLine);
        results.Next;
      end;
    finally
      names.Free;
    end;
  end;
end;

例外“没有这样的表：Table_Name”

1 个答案: