LocalSQL使用

http://docwiki.embarcadero.com/Libraries/Tokyo/en/FireDAC.Phys.SQLiteVDataSet.TFDLocalSQL

http://docwiki.embarcadero.com/RADStudio/Tokyo/en/Local_SQL_(FireDAC)

The Local SQL is based on the SQLite database and supports most of the SQLite SQL dialect. As table name, it uses the name of a TDataSet (Name property value) or, alternatively, a specified name. Each queryable dataset must be registered with TFDLocalSQL, the Local SQL engine.

// setup connection and query to "Orders" table

ADOQuery1.SQL.Text := 'select * from Orders';

// link dataset to Local SQL engine

with FDLocalSQL1.DataSets.Add do begin

DataSet := ADOQuery1;

Name := 'Orders';

end;

   

// setup connection and query to "Order Details" table

ADOQuery2.SQL.Text := 'select * from "Order Details"';

// link dataset to Local SQL engine

with FDLocalSQL1.DataSets.Add do begin

DataSet := ADOQuery2;

Name := 'Order Details';

end;

   

// setup SQLite in-memory connection

FDConnection1.DriverName := 'SQLite';

FDConnection1.Connected := True;

// link Local SQL to SQLite connection

FDLocalSQL1.Connection := FDConnection1;

FDLocalSQL1.Active := True;

   

// execute SELECT query on above datasets

FDQuery1.Connection := FDConnection1;

FDQuery1.SQL.Text := 'SELECT * FROM Orders o LEFT JOIN "Order Details" od ON o.OrderID = od.OrderID';

FDQuery1.Active := True;