实例讲解Oracle到SQL Server主键迁移（2）

procedure TForm1.Button1Click(Sender: TObject);

var

i:Integer;

FieldN, tableN, fieldM,aa:String;

begin

if Not ADOConnOrcale.Connected then

begin

MsgBox('请先连接Oracle数据库!');

exit;

end;

if not ADOConnSQLServer.Connected then

begin

MsgBox('请先连接SQL Server数据库!');

exit;

end;

Screen.Cursor :=crHourGlass;

try

o1.Close;

O1.SQL.Clear;

//取oracle表用户budget的所有主键约束信息

o1.SQL.Text :=' select a.CONSTRAINT_NAME,a.CONSTRAINT_TYPE,a.TABLE_NAME, b.COLUMN_NAME,b.position '+

' from USER_CONSTRAINTS a,USER_CONS_COLUMNS b where a.CONSTRAINT_NAME=b.CONSTRAINT_NAME '+

' and a.table_name=b.table_name and constraint_type=''P'' and a.owner=b.owner '+

' and lower(a.owner)=''budget'' order by a.table_name,b.position ';

O1.open;

tableN:='';

O1.First;

ProgressBar1.Max:=O1.RecordCount;

ProgressBar1.Min:=0;

ProgressBar1.Step:=1;

ProgressBar1.Visible :=true;

for i:=0 to O1.RecordCount -1 do

begin

s2.Close;

S2.SQL.Clear;

//判断SQL Server表是否存在当前的字段信息

S2.SQL.Text:='SELECT a.name AS tanme, b.* FROM sysobjects a INNER JOIN '+

' syscolumns b ON a.id = b.id '+

' WHERE (a.xtype = ''U'') AND (a.name = '''+O1.fieldbyname('table_name').AsString+''''+

') and b.name= '''+O1.fieldbyname('COLUMN_NAME').AsString+''''+

' ORDER BY b.id';

S2.Open;

//不存在，输出表明和字段名

if s2.RecordCount<=0 then

begin

Memo1.Text:=Memo1.Text+#13+'表：'''+O1.fieldbyname('table_name').AsString+''''+

' 字段：'''+O1.fieldbyname('COLUMN_NAME').AsString+''' 不存在!';

O1.Next;

tableN:='';

FieldN:='';

Continue;

end;

//是当前表，循环读取主键信息

if (tableN='') or (tableN= O1.fieldbyname('table_name').AsString) then

begin

FieldN:=FieldN+'['+O1.fieldbyname('COLUMN_NAME').AsString+'],';//表明相同或初试时

tableN:= O1.fieldbyname('table_name').AsString;

end

else

begin

with S1 do

begin

try

//取SQL Server表的主键信息

Close;

sql.Clear;

sql.Text:='SELECT * FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE TABLE_NAME='''+tableN+'''';

Open;

first;

aa:=fieldbyname('constraint_name').AsString;

//如果该主键在SQL表中已存在，删除该主键信息,重建该表主键

if recordcount>0 then

begin

sql.Clear;

SQL.Text:='ALTER TABLE '+tableN+' DROP CONSTRAINT '+aa; //删除主键

ExecSQL;

end;

SQL.Clear; //COLUMN_NAME

SQL.Text:='ALTER TABLE '+tableN+' WITH NOCHECK ADD '+

' CONSTRAINT [PK_'+tableN+'] PRIMARY KEY NONCLUSTERED '+

' ( '+ copy(FieldN,1,length(FieldN)-1)+

' )';

ExecSQL;

FieldN:='['+O1.fieldbyname('COLUMN_NAME').AsString+'],';

tableN:= O1.fieldbyname('table_name').AsString;

Except

Memo1.Text :=Memo1.Text+'表： '+tableN+' 字段： '+FieldN+' 导入出错!';

exit;

end;

end;

end;

ProgressBar1.StepIt;

Application.ProcessMessages;

O1.Next;

end;

MsgBox('导入完成!');

finally

Screen.Cursor :=crDefault;

ProgressBar1.Visible :=False;

end;

end;