Devart Forums

I'm working with SQL server.
If I try to do an INSERT like this:

TUniSQL *UniSQL = new TUniSQL(NULL);
UniSQL->Connection = UniConnection1;
UniSQL->Debug = true;
UniSQL->ParamCheck = false;
AnsiString text = "INSERT INTO AgeCategories VALUES (:AgeCategoryId, :AgeCategoryName, :LocalizedAgeCategoryName)";
UniSQL->SQL->Clear();
UniSQL->SQL->Add(text);
UniSQL->ParamCheck = true;
UniSQL->Prepared = true;
UniSQL->Params->ParamByName("AgeCategoryId")->AsString = "AA";
UniSQL->Params->ParamByName("AgeCategoryName")->AsString = "TEST";
UniSQL->Params->ParamByName("LocalizedAgeCategoryName")->AsString = AnsiString("a");

UniConnection1->StartTransaction();
try
{
UniSQL->Execute();
UniConnection1->Commit();
}
catch (Exception *E)
{
UniConnection1->Rollback();
throw E;
}

I get an exeption:

Project TestSQLServer.exe raised exception class EUniError with message 'Statement(s) could not be prepared.
Implicit conversion from data type sql_variant to varchar is not allowed. Use the CONVERT function to run this query.'. Process stopped. Use Step or Run to continue.

The table schema is the following:

CREATE TABLE [dbo].[AgeCategories](
[AgeCategoryId] [varchar](2) NOT NULL,
[AgeCategoryName] [nvarchar](50) NOT NULL,
[LocalizedAgeCategoryName] [nvarchar](50) NULL,
CONSTRAINT [PK_AgeCategories] PRIMARY KEY CLUSTERED
(
[AgeCategoryId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

It works if I execute visually on the form.

Regards

To avoid this error message, you should set the TUniSQL->Prepared property in your code sample to true after you assign values to all the parameters. Taking into account this edit, your code will look like the following:

Thank you, works fine.
Another question: should I use one connection for each thread or just one for all?

A separate TUniConnection instance must be used for each thread in a multi-threaded application.

Thank you.

Just one question

I have a TUniConnection in my c++ form

object UniConnection1: TUniConnection
ProviderName = 'SQL Server'
Database = 'RaceManagerDevelopment'
SpecificOptions.Strings = (
'SQL Server.Authentication=auWindows')
Pooling = True
Server = 'NB-ALESSANDROM\SQLEXPRESS'
Connected = True
LoginPrompt = False
Left = 424
Top = 168
end

And I can connect this component to the sql server database.
But if I do that in the code

TUniConnection* _uniConnection = new TUniConnection(NULL);
_uniConnection->ConnectString= "Provider Name=SQL Server;Login Prompt=False;Pooling=True;Data Source=NB-ALESSANDROM\SQLEXPRESS;Initial Catalog=RaceManagerDevelopment;Port=0;Integrated Security=SSPI";
_uniConnection->SpecificOptions->Add("SQL Server.Authentication=auWindows");
_uniConnection->Connect();

I receive this error

'Named Pipes Provider: Could not open a connection to SQL Server [53]. '

What is wrong?

Thank you, I see now ... should be "NB-ALESSANDROM\\SQLEXPRESS" instead of "NB-ALESSANDROM\SQLEXPRESS"

I took this string from inspector.

Now it works

Thank you again for your support

Glad to see that the issue was resolved. If any other questions come up, please contact us.