SQL

[Neville]

Using TSQLQuery with Helen Borrie's SQL, The process fails at the line ending 'First'; "Operation cannot be performed on an inactive dataset."
I got no complaint at the ExecSQL line.

What could be the problem?

   FirebirdUtilsForm.FirebirdQuery.SQL.clear;
   FirebirdUtilsForm.FirebirdQuery.SQL.text := 'select rdb$relation_name,rdb$field_name,rdb$constraint_name ' +
                                               'from rdb$relation_constraints rc,rdb$index_segments ri ' +
                                               'where ri.rdb$index_name = rc.rdb$index_name order by rdb$relation_name';
   FirebirdUtilsForm.FirebirdQuery.ExecSQL;
   FirebirdUtilsForm.FirebirdQuery.First;
   while not FirebirdUtilsForm.FirebirdQuery.EOF do
   begin

[dsiders]

Using TSQLQuery with Helen Borrie's SQL, The process fails at the line ending 'First'; "Operation cannot be performed on an inactive dataset."
I got no complaint at the ExecSQL line.

What could be the problem?

   FirebirdUtilsForm.FirebirdQuery.SQL.clear;
   FirebirdUtilsForm.FirebirdQuery.SQL.text := 'select rdb$relation_name,rdb$field_name,rdb$constraint_name ' +
                                               'from rdb$relation_constraints rc,rdb$index_segments ri ' +
                                               'where ri.rdb$index_name = rc.rdb$index_name order by rdb$relation_name';
   FirebirdUtilsForm.FirebirdQuery.ExecSQL;
   FirebirdUtilsForm.FirebirdQuery.First;
   while not FirebirdUtilsForm.FirebirdQuery.EOF do
   begin

ExecSQL is for statements that do not return a result set.
https://lazarus-ccr.sourceforge.io/docs/fcl/sqldb/tcustomsqlquery.execsql.html

Set Active to True to open the result set.

[Neville]

Many thanks.  That works fine (of course).