I have a stored procedure with this signature:
CREATE PROCEDURE SI_Inteligence(#dt datetime, #actions varchar(6), #FullData cursor varying out)
This procedure returns an open cursor.
What kind of component do I need to trap it and iterate over it record by record? It's only a parameter from stored procedure!
procedure DoIt;
var sp: TADOStoredProc;
x: TADODataSet; //?
begin
sp := TADOStoredProc.Create(Self);
sp.Connection := myConnection; //TADOConnection Component
sp.ProcedureName := 'SI_Inteligence';
sp.Parameters.ParamByName('#dt').Value := date;
sp.Parameters.ParamByName('#actions').Value := 'something';
sp.ExecProc;//? Open doesn't return anything
x := TADODataSet.Create(Self);
//How load the cursor??
x.Assign(sp.Parameters.ParamByName('#FullData') as TADODataSet); //crash
end;
Now I need loop that cursor. How can I do that?
The CURSOR params are returned as recordsets, So you can iterate over the data using the TADOStoredProc methods related to the TDataSet class like Eof, Next, FieldByName and so on.
Try this code .
ADOStoredProc1.ExecProc;
while not ADOStoredProc1.Eof do
begin
//do something
//ADOStoredProc1.FieldByName('Foo').Value;
ADOStoredProc1.Next;
end;
if the stored procedure return more than a cursor, you can iterate over the recordsets using the NextRecordset method as is described on this post.
Related
To pass an array of number to oracle stored procedure, I created a type like this:
create or replace type wareconfig_array as table of NUMBER;
Then I created my procedure like this, when I compile, it shows success, then I pass an array like: [1,2] to m_array when I run it, it throws an error: "ORA-06531:Reference to uninitialized collection" Can you tell me what I did wrong? Thanks very much!
create or replace procedure delete_waregroup(m_array in wareconfig_array) is
begin
for i in 1..m_array.count loop
update "warehouse_group" set "deleted"=1 where "id"=m_array(i);
end loop;
commit;
EXCEPTION
when others THEN
save_proc_error('proc',sqlcode,'删除仓库组信息发生异常！',sqlerrm);
raise_application_error(-20003,'数据操作异常！异常编码：'|| sqlcode || '异常描述：'|| sqlerrm||dbms_utility.format_error_backtrace());
rollback; ---回滚
end delete_waregroup;
Try:
declare
x wareconfig_array;
begin
x := wareconfig_array(1,3); -- initialize an array and fill it with values
delete_waregroup( x );
end;
/
live (working) demo: http://sqlfiddle.com/#!4/af403e/1
I am trying to update two different SQL tables in the same loop using parameterized queries in Delphi XE8. I also want to wrap the whole thing in a transaction, so that if anything in the loop fails, neither table gets updated.
I don't really know what I'm doing, would appreciate some help.
The code below is a simplified version of what I'm trying to achieve, and my best guess as to how to go about it. But I'm not really sure of it at all, particularly the use of two datasets connected to the 'SQL connection' component.
SQL_transaction.TransactionID :=1;
SQL_transaction.IsolationLevel:=xilREADCOMMITTED;
SQL_connection.BeginTransaction;
Try
{ Create connections }
SQL_dataset1 :=TSQLDataSet.Create(nil);
SQL_dataset1.SQLConnection:=SQL_connection;
SQL_dataset2 :=TSQLDataSet.Create(nil);
SQL_dataset2.SQLConnection:=SQL_connection;
{ Create queries }
SQL_dataset1.CommandType:=ctQuery;
SQL_dataset1.CommandText:={ some parameterized query updating table A }
SQL_dataset2.CommandType:=ctQuery;
SQL_dataset2.CommandText:={ some parameterized query updating table B }
{ Populate parameters and execute }
For I:=0 to whatever do
begin
SQL_dataset1.ParamByName('Table A Field 1').AsString:='Value';
SQL_dataset1.ExecSQL;
SQL_dataset2.ParamByName('Table B Field 1').AsString:='Value';
SQL_dataset2.ExecSQL;
end;
SQL_connection.Commit(SQL_transaction);
except
SQL_connection.Rollback(SQL_transaction);
end;
I am using Delphi XE8, and the database can be either SQL server or SQLite.
The logic of your transaction handling is correct (except the missing exception re-raise mentioned by #whosrdaddy). What is wrong are missing try..finally blocks for your dataset instances. Except that you should stop using TSQLConnection deprecated methods that are using the TTransactinDesc record (always check the compiler warnings when you're building your app.). And you can also switch to TSQLQuery component. Try something like this instead:
var
I: Integer;
Query1: TSQLQuery;
Query2: TSQLQuery;
Connection: TSQLConnection;
Transaction: TDBXTransaction;
begin
...
Query1 := TSQLQuery.Create(nil);
try
Query1.SQLConnection := Connection;
Query1.SQL.Text := '...';
Query2 := TSQLQuery.Create(nil);
try
Query2.SQLConnection := Connection;
Query2.SQL.Text := '...';
Transaction := Connection.BeginTransaction;
try
// fill params here and execute the commands
for I := 0 to 42 to
begin
Query1.ExecSQL;
Query2.ExecSQL;
end;
// commit if everything went right
Connection.CommitFreeAndNil(Transaction);
except
// rollback at failure, and re-raise the exception
Connection.RollbackFreeAndNil(Transaction);
raise;
end;
finally
Query2.Free;
end;
finally
Query1.Free;
end;
end;
I prefer try finally over try except
here's how to make it work in a try finally block
var
a_Error: boolean;
begin
a_Error := True;//set in error state...
SQL_dataset1 := nil;
SQL_dataset2 := nil;
SQL_transaction.TransactionID :=1;
SQL_transaction.IsolationLevel:=xilREADCOMMITTED;
SQL_connection.BeginTransaction;
Try
{ Create connections }
SQL_dataset1 :=TSQLDataSet.Create(nil);
SQL_dataset1.SQLConnection:=SQL_connection;
SQL_dataset2 :=TSQLDataSet.Create(nil);
SQL_dataset2.SQLConnection:=SQL_connection;
{ Create queries }
SQL_dataset1.CommandType:=ctQuery;
SQL_dataset1.CommandText:={ some parameterized query updating table A }
SQL_dataset2.CommandType:=ctQuery;
SQL_dataset2.CommandText:={ some parameterized query updating table B }
{ Populate parameters and execute }
For I:=0 to whatever do
begin
SQL_dataset1.ParamByName('Table A Field 1').AsString:='Value';
SQL_dataset1.ExecSQL;
SQL_dataset2.ParamByName('Table B Field 1').AsString:='Value';
SQL_dataset2.ExecSQL;
end;
a_Error := False;//if you don't get here you had a problem
finally
if a_Error then
SQL_connection.Rollback(SQL_transaction)
else
SQL_connection.Commit(SQL_transaction);
SQL_dataset1.Free;
SQL_dataset2.Free;
end;
end;
I added some code on how Try Finally works with init objects to nil
TMyObject = class(TObject)
Name: string;
end;
procedure TForm11.Button1Click(Sender: TObject);
var
a_MyObject1, a_MyObject2: TMyObject;
begin
a_MyObject1 := nil;
a_MyObject2 := nil;
try
a_MyObject1 := TMyObject.Create;
a_MyObject1.Name := 'Object1';
if Sender = Button1 then
raise exception.Create('Object 2 not created');
ShowMessage('We will not see this');
a_MyObject2 := TMyObject.Create;
a_MyObject2.Name := 'Object2';
finally
a_MyObject2.Free;
ShowMessage('We will see this even though we called a_MyObject2.free on a nil object');
a_MyObject1.Free;
end;
end;
Below is the SQL Server's syntax to select variable as a record
DECLARE #number AS INTEGER;
SET #number = 10;
SELECT #number;
How can I do this in ORACLE?
Thanks in advance.
Regards,
Sagar Nannaware
Edited based on comment:
One way you can access the variable value assigned by a procedure is through a function again.
Example:
CREATE OR REPLACE PROCEDURE your_procedure(out_number OUT number)
IS
BEGIN
out_number:=1;
END;
function to retrieve the procedure's output
CREATE OR REPLACE FUNCTION your_function
RETURN number
AS
o_param number;
BEGIN
o_param := NULL;
your_procedure(o_param);
RETURN o_param;
EXCEPTION
WHEN NO_DATA_FOUND
THEN
return 0; --basically how you want to handle your errors.
END your_function;
Now you can select the output of the procedure
select your_function from dual;
Useful link how to access an Oracle procedure's OUT parameter when calling it?
If you are trying to create a variable to access anywhere in your application in oracle.
You can do it by creating function and calling it from dual.
SQL>create or replace function foo return number
as
x number;
begin
x:=1;
return 1;
end;
Function created.
SQL>select foo from dual;
FOO
----------
1
Please check following link for more details
[example link] (http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:1562813956388)
I'm having yet another problem with Delphi. I wrote a piece of code that should check if a field in a database table equals to 0, and if that is true, changes font color and caption of a certain button. It runs on creation of the main form. However, when I run the program, nothing happens - the program does not appear and I get no errors. I seriously don't know what's wrong, seems like some kind of an infinite loop.
Here's the code:
procedure TForm1.FormCreate(Sender: TObject);
begin
ADOTableStorage.First;
while not ADOTableStorage.Eof do
If ADOTableStorage.FieldByName('amount').AsInteger = 0 then
begin
btStorage.Font.Color := clRed;
btStorage.Caption := 'Some items are out of stock!';
Break;
end;
ADOTableStorage.Next;
end;
Note: The ADOTableStorage table is a on the detail table in a Master-Detail connection.
Thanks!
I guess you are missing a begin/end in the while loop. Try this.
procedure TForm1.FormCreate(Sender: TObject);
begin
ADOTableStorage.First;
while not ADOTableStorage.Eof do
begin
If ADOTableStorage.FieldByName('amount').AsInteger = 0 then
begin
btStorage.Font.Color := clRed;
btStorage.Caption := 'Some items are out of stock!';
Break;
end;
ADOTableStorage.Next;
end;
end;
Some of my MS SQL stored procedures produce messages using the 'print' command. In my Delphi 2007 application, which connects to MS SQL using TADOConnection, how can I view the output of those 'print' commands?
Key requirements:
1) I can't run the query more than once; it might be updating things.
2) I need to see the 'print' results even if datasets are returned.
That was an interesting one...
The OnInfoMessage event from the ADOConnection works but the Devil is in the details!
Main points:
use CursorLocation = clUseServer instead of the default clUseClient.
use Open and not ExecProc with your ADOStoredProc.
use NextRecordset from the current one to get the following, but be sure to check you have one open.
use SET NOCOUNT = ON in your stored procedure.
SQL side: your stored procedure
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[FG_TEST]') AND type in (N'P', N'PC'))
DROP PROCEDURE [dbo].[FG_TEST]
GO
-- =============================================
-- Author: François
-- Description: test multi ADO with info
-- =============================================
CREATE PROCEDURE FG_TEST
AS
BEGIN
-- SET NOCOUNT ON absolutely NEEDED
SET NOCOUNT ON;
PRINT '*** start ***'
SELECT 'one' as Set1Field1
PRINT '*** done once ***'
SELECT 'two' as Set2Field2
PRINT '*** done again ***'
SELECT 'three' as Set3Field3
PRINT '***finish ***'
END
GO
Delphi side:
Create a new VCL Forms Application.
Put a Memo and a Button in your Form.
Copy the following text, change the Catalog and Data Source and Paste it onto your Form
object ADOConnection1: TADOConnection
ConnectionString =
'Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security In' +
'fo=False;Initial Catalog=xxxYOURxxxDBxxx;Data Source=xxxYOURxxxSERVERxxx'
CursorLocation = clUseServer
LoginPrompt = False
Provider = 'SQLOLEDB.1'
OnInfoMessage = ADOConnection1InfoMessage
Left = 24
Top = 216
end
object ADOStoredProc1: TADOStoredProc
Connection = ADOConnection1
CursorLocation = clUseServer
ProcedureName = 'FG_TEST;1'
Parameters = <>
Left = 24
Top = 264
end
In the OnInfoMessage of the ADOConnection put
Memo1.Lines.Add(Error.Description);
For the ButtonClick, paste this code
procedure TForm1.Button1Click(Sender: TObject);
const
adStateOpen = $00000001; // or defined in ADOInt
var
I: Integer;
ARecordSet: _Recordset;
begin
Memo1.Lines.Add('==========================');
ADOStoredProc1.Open; // not ExecProc !!!!!
ARecordSet := ADOStoredProc1.Recordset;
while Assigned(ARecordSet) do
begin
// do whatever with current RecordSet
while not ADOStoredProc1.Eof do
begin
Memo1.Lines.Add(ADOStoredProc1.Fields[0].FieldName + ': ' + ADOStoredProc1.Fields[0].Value);
ADOStoredProc1.Next;
end;
// switch to subsequent RecordSet if any
ARecordSet := ADOStoredProc1.NextRecordset(I);
if Assigned(ARecordSet) and ((ARecordSet.State and adStateOpen) <> 0) then
ADOStoredProc1.Recordset := ARecordSet
else
Break;
end;
ADOStoredProc1.Close;
end;
In .net's connection classes there is an event called InfoMessage. In a handler for this event you can retrieve the InfoMessage (print statements) from the event args.
I believe Delphi has a similar event called "OnInfoMessage" that would help you.
I dont think that is possible.
You might use a temp table to dump print statements and return it alongwith results.
Some enhancements to Francois' code (as tested with DXE2) to cater for multiple print statements and the results from a variable number of selects. The changes are subtle.
procedure TForm1.ADOConnection1InfoMessage(Connection: TADOConnection;
const Error: Error; var EventStatus: TEventStatus);
var
i: integer;
begin
// show ALL print statements
for i := 0 to AdoConnection1.Errors.Count - 1 do
begin
// was: cxMemo1.Lines.Add(Error.Description);
cxMemo1.Lines.Add(
ADOConnection1.Errors.Item[i].Description);
end;
end;
procedure TForm1.cxButton1Click(Sender: TObject);
const
adStateOpen = $00000001; // or uses ADOInt
var
records: Integer;
ARecordSet: _RecordSet;
begin
cxMemo1.Lines.Add('==========================');
ADOStoredProc1.Open;
try
ARecordSet := ADOStoredProc1.RecordSet; // initial fetch
while Assigned(ARecordSet) do
begin
// assign the recordset to a DataSets recordset to traverse
AdoDataSet1.Recordset := ARecordSet;
// do whatever with current ARecordSet
while not ADODataSet1.eof do
begin
cxMemo1.Lines.Add(ADODataSet1.Fields[0].FieldName +
': ' + ADODataSet1.Fields[0].Value);
AdoDataSet1.Next;
end;
// fetch next recordset if there is one
ARecordSet := ADOStoredProc1.NextRecordSet(records);
if Assigned(ARecordSet) and ((ARecordSet.State and adStateOpen) <> 0) then
ADOStoredProc1.Recordset := ARecordSet
else
Break;
end;
finally
ADOStoredProc1.Close;
end;
end;