Re: Gnade/ODBC example - please help

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

Hubert Walter wrote:
> And now my problem: This example shows how to pass integer parameter
> to the query and get string and float from the database.
> I trying to pass to the query string and the boolean (...WHERE NAME =
> name AND IsVisible = visible...) and I can't. I have no idea how to
> rewrite this example.

The example already covers getting Strings from the database. To bind
a String into a query, you simply call the procedure
GNU.DB.SQLCLI.SQLBindParameter where the Value parameter has type
"access String" (line 765 in gnu-db-sqlcli.ads). This would look like:

Some_String : aliased String := "this is the string I want to bind
into the prepared statement";
Length : aliased SQLINTEGER := Some_String'Length;

SQLPrepare (StatementHandle, "SELECT * FROM T WHERE NAME = ? AND
IS_VISIBLE = ?);
SQLBindParameter
  (StatementHandle,
   ParameterNumber => 1,
   Value => Some_String'Access,
   Length => Lengh'Access);

As for Booleans, I think the best option is to instantiate
GNU.DB.SQLCLI.EnumBinding (line 866 in gnu-db-sqlcli.ads) using
Boolean as the parameter, like so:

package Boolean_Binding is new GNU.DB.SQLCLI.EnumBinding (Enum =>
Boolean);
Indicator : aliased SQLINTEGER;

Boolean_Binding.SQLBindParameter
  (StatementHandle,
   ParameterNumber => 2,
   Value => Some_Boolean'Access,
   SQLIndicator => Indicator'Access);

Hope this helps

--
Ludovic Brenta.