Create table with firedac without SQL Script

问题

Firedac library centralizes database behavior and have a lot of methods which works fine without care about the Database Type. Actually, using native drivers for most common databases, Firedac hides subtle differences on syntax allowing very flexible changes of database platform.
For example, generators and autoinc fields are easily detectable, CAST and parameters works fine allowing easy migration between databases.

How to use Firedac power to create New Table without instantiate FDQuery, which runs a SQL Script CREATE TABLE?

I hope to create any Object and, calling specific FieldByName for each Object Field, record it on database, but first I need to certify:

If Table is already created
If Field is already created
If record is already created

This is the code I have, so far:

TRecCustomer = record
  Id:integer;
  Name:String;
  Birthday:TDate;
end;

ICustomer = interface
  procedure setCustomerId(Value: Integer);
  procedure setCustomerName(Value: String);
  procedure SetBirthday(Value: TDate);
  procedure Post;
end;

TCustomer = class(TInterfacedObjet, ICustomer)
  CustomerObject=TRecCustomer;

  procedure setCustomerId(Value: Integer);
  procedure setCustomerName(Value: String);
  procedure SetBirthday(Value: TDate);
  procedure Post;
end;

procedure TCustomer.Post;
begin
  if not TableExists('Customer') then CreateTable('Customer');
  if not FieldExists('Name') then CreateField('Customer','name',ftString,[],40);
  if not FieldExists('Id') then CreateField('Customer','Id',ftInteger,[cAutoInc,cNotNull]);
  if not FieldExists('Birthday') then CreateField('Customer','birthday',ftDate);
end;

Imagine the procedures

CreateTable(Tablename: String)
CreateField(FieldName: String; FieldType: TDataType; Constraints: TConstraints; Length: Integer = 0);

where

TConstraints = set of (cAutoInc, cNotNull, cUnique, cEtc);

I can do it for specific database, for example Sqlite or Firebird, but I don't know hou to do for any database using Firedac resources.

I found FireDAC.Comp.Client.TFDTable.CreateTable(ARecreate: Boolean = True; AParts: TFDPhysCreateTableParts = [tpTable .. tpIndexes]), suggested by @Ondrej Kelle but I don't understood AParts usage. Somebody have an example? http://docwiki.embarcadero.com/Libraries/Berlin/en/FireDAC.Comp.Client.TFDTable.CreateTable

Thanks a lot.

回答1:

You can create a TFDTable object, describe your table at least by specifying TableName and adding field definitions in the FieldDefs collection. In practice you'll usually create also a primary key index for some field (that's what can be done by the AddIndex method). After you describe your table, call CreateTable method. A minimal example can be:

var
  Table: TFDTable;
begin
  Table := TFDTable.Create(nil);
  try
    Table.Connection := FDConnection1;
    { specify table name }
    Table.TableName := 'MyTable';
    { add some fields }
    Table.FieldDefs.Add('ID', ftInteger, 0, False);
    Table.FieldDefs.Add('Name', ftString, 50, False);
    { define primary key index }
    Table.AddIndex('pkMyTableID', 'ID', '', [soPrimary]);
    { and create it; when the first parameter is True, an existing one is dropped }
    Table.CreateTable(False);
  finally
    Table.Free;
  end;
end;

来源：https://stackoverflow.com/questions/43971503/create-table-with-firedac-without-sql-script

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