DBEXPRESS: Operation not allowed on unidirectional dataset

[Guest_imported]

I put a datasource, sqlconnection, sqlquery and a dbgrid,
and when I try to change dbgrid datasource it tells me:
"Operation not allowed on unidirectional dataset"

What is the solution to this!

 

[Dooda]

I haven't used dbexpress, but have seen changing the datasource of a Tquery fail if the Tquery was not first made inactive.

 

[TimSNL]

"Operation not allowed on unidirectional dataset"

A unidirectional dataset can only move through records in one direction, not back and forward. A grid can move in both directions and so can't be connected to a unidirectional dataset.

You realy need to read the "Developers Guide", part II, 'Developing Database Applications', page 14-6.

To use a grid you need these components ...
SQLQuery
DataSetProvider
ClientDataSet
DataSource
DBGrid

This can also be achieved by using the TSQLClientDatSet which murges the first 3 components in the above list into 1.

Tim Dover