Update table at run-time
lazarus / 16-Databases

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babycode · 2024-05-21 23:17

I'm trying to update a table at runtime using a temporary Query. In
the end it does not show any errors or exceptions, but when I query
the table the information has not been updated. Basically I'm updating
just one field, I created the connection and the query at run time, I
execute the sql, and I destroy the components, but the information is
not updated in the database. 

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
GravarMD5P(session_p: string; u_id: integer);var        qryTemp:
TZQuery;        conTemp: TZConnection;begin        qryTemp :=
TZQuery.Create(Nil);        conTemp := CriarConexaoSec;        
qryTemp.Connection := conTemp;        qryTemp.CachedUpdates := False; 
      ConTemp.Connect;         try                with qryTemp do    
          begin                        SQL.Clear;                    
   Connection.StartTransaction;                        
SQL.Add('update usuarios set sessao_p = :sSession_p where usuario_id =
:iUsuarioID;');                       
ParamByName('sSession_p').AsString := 'ttaassttes';                  
    ParamByName('iUsuarioID').AsInteger := 1;                        
try                                ExecSQL;                          
    ApplyUpdates;                                Connection.Commit;  
                    except                                on E:
Exception do                                begin                    
                  ShowMessage('Erro ao gravar dados: ' + E.Message); 
                                     Connection.Rollback; // Desfaz a
transação em caso de erro                                end;        
              end;                end;        finally               
conTemp.Free;                qryTemp.Free;        end;end; 

I checked if SQL.Text is correct and if it is receiving the values
​​in the procedure parameters and they are. It simply doesn't show an
error or exception, it doesn't record  . I'm using ZeosLib 8. Sorry
for not including a minimal example, I'm using PostgreSQL.

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egsuh · 2024-05-22 03:28

1. Where is the qryTemp created?
2. Do not use ApplyUpdates if you are directly operating on a SQL DB
with SQL statements.
3. Not sure these are supported in ZQuery, but basics are
Transaction.StartTransaction and Transaction.Commit. You are using
Connection.StartTransaction and Connection.Commit.

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babycode · 2024-05-22 12:57

Quote from: egsuh on May 22, 2024, 05:28:41 am1. Where is the qryTemp
created?
2. Do not use ApplyUpdates if you are directly operating on a SQL DB
with SQL statements.
3. Not sure these are supported in ZQuery, but basics are
Transaction.StartTransaction and Transaction.Commit. You are using
Connection.StartTransaction and Connection.Commit.

The TZConnection component has the transaction option, but I did a
test after your answer and also created a TZTransaction at run time
and placed it for the TZConnection. I explicitly controlled the
transaction using the transaction created and the information was
saved in the bank correctly. Apparently I need the transaction even at
run time.

1. The temporary query is created here:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
GravarMD5P(session_p: string; u_id: integer);var        qryTemp:
TZQuery; // defines the type of TZQuery variable        conTemp:
TZConnection; begin        qryTemp := TZQuery.Create(Nil); //creates
an instance of the TZQuery class and assigns it to the variable.
2. I only used ApplyUpdates as a test, but in ZeosLib I generally use
Query.CommitUpdates
Transaction.Commit.