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delphi FireDAC 下的 Sqlite [5] - 数据的插入、更新、删除

作者:admin 来源: 日期:2018/3/14 8:21:45 人气: 标签:

先在空白窗体上添加: TFDConnection、TFDPhysSQLiteDriverLink、TFDGUIxWaitCursor、TFDQuery、TDataSource、TDBGrid(并在设计时关联好).

代码:

{建立}

procedure TForm1.FormCreate(Sender: TObject);

const

  dbPath = 'C:\Temp\SQLiteTest.sdb';

  strTable = 'CREATE TABLE MyTable(Id integer PRIMARY KEY AUTOINCREMENT, Name string(10), Age byte)'; //Id, Name, Age 三个字段

                                                                                                      //integer PRIMARY KEY AUTOINCREMENT: 自增字段

begin

  if FileExists(dbPath) then DeleteFile(dbPath);

 

  FDConnection1.ConnectionString := 'DriverID=SQLite; Database=' + dbPath;

  FDConnection1.ExecSQL(strTable);

 

  FDQuery1.Open('SELECT * FROM MyTable');

end;

 

{插入}

procedure TForm1.Button1Click(Sender: TObject);

const

  strInsert = 'INSERT INTO MyTable(Name, Age) VALUES(:name, :age)'; //:name, :age 的方式(后面还要以数组的方式给出相应的值), 这比字符串的 Format 函数还要方便.

begin

  FDConnection1.ExecSQL(strInsert, ['AAA', 11]);

  FDConnection1.ExecSQL(strInsert, ['BBB', 22]);

  FDConnection1.ExecSQL(strInsert, ['CCC', 33]);

  FDConnection1.ExecSQL(strInsert, ['DDD', 44]);

  FDConnection1.ExecSQL(strInsert, ['EEE', 55]);

  FDQuery1.Refresh;

end;

 

{更新}

procedure TForm1.Button2Click(Sender: TObject);

begin

  FDConnection1.ExecSQL('UPDATE MyTable SET Age=:a WHERE Name=:n', [Random(100), 'AAA']);

  FDQuery1.Refresh;

end;

 

{删除}

procedure TForm1.Button3Click(Sender: TObject);

begin

  FDConnection1.ExecSQL('DELETE FROM MyTable WHERE Age>33');

  FDQuery1.Refresh;

end;

 

{查询符合条件的第一个结果}

procedure TForm1.Button4Click(Sender: TObject);

var

  V: Variant;

begin

  V := FDConnection1.ExecSQLScalar('SELECT Age FROM MyTable WHERE Name = :x', ['BBB']);

  ShowMessage(V);

end;

 

//:

select * from test where name = 'ABCDE' COLLATE NOCASE;

create table test (id Integer,name Text COLLATE NOCASE );


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