How to insert a row (not record) into TDBGrid [SOLVED]
lazarus / 16-Databases

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PaulW · 2011-05-22 23:49

I have a TDBGrid that I populate with the results of a query.  If the
query returns no records, I want to populate the TDBGrid with one row.
 I've tried to use
   MyGrid.InsertRecord([1,'two','three']);
     or
   MyGrid_DataSource.DataSet.InsertRecord([1,'two','three']);
Both result in an error: Cannot update a complex query with more than
one table   

Should I somehow unbound the grid from it's datasource?  If so, then
could I just use MyGrid.InsertRecord()?

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exdatis · 2011-05-23 05:15

Use UpdateQuery with query(update object = update_query)

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PaulW · 2011-05-23 21:56

Thanks.  I'll look into your suggestion.

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99Percent · 2011-05-24 05:12

use TBufDataSet or TMemDataSet and then switch the datasource to it
before inserting a record. You will need to define the fields to be
the same.

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JD · 2011-05-24 10:38

Quote from: PaulW on May 23, 2011, 01:49:52 amI have a TDBGrid that I
populate with the results of a query.  If the query returns no
records, I want to populate the TDBGrid with one row.  I've tried to
use
   MyGrid.InsertRecord([1,'two','three']);
     or
   MyGrid_DataSource.DataSet.InsertRecord([1,'two','three']);
Both result in an error: Cannot update a complex query with more than
one table   

Should I somehow unbound the grid from it's datasource?  If so, then
could I just use MyGrid.InsertRecord()?   

I once had this problem because I had a form with several TEdit fields
and a TDBGrid which was supposed to be updated from a query on 4
different tables. The TEdit fields & the TDBGrid had the same
datasource. I kept getting the error "cannot update a complex query
with more than one table" everytime I tried to update the TDBGrid.

I solved the problem by creating a new datasource & a new query unique
to the TDBGrid.

That may work for you. If it dosen't, post a sample of your code so we
can better understand the problem.

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PaulW · 2011-05-25 20:08

Thanks for the suggestions.  I'll dig into them and see how it goes.
 For now, I solved my problem by using an alternative query:
If the first query returns a record, I fetch the fields for the grid
from a table using the second query and a where clause based on the
values from the first query.  If the first query returns no records, I
fetch the fields for the grid from the table using a modified second
query that I force to get the fields I want by hard-coding the where
clause.  Certainly not a very elegant approach, but i works.  I'll do
some more experimentation using the suggestions provided.  I'll mark
this issue "solved".