>>>>>I am trying to implement a simple 'multiple select mover grid' and I find the re-sequencing of the record slow. I am sure there is a way to re-order the records in a shorter time. Can somebody help?
>>>>>
>>>>>I keep a sequence number in the table to order the table. First, the user selects a few records by clicking on the checkbox (flag). Then the user selects the new position for the selected records. When the 'Move' button is click, I tried to sequence it using the following codes
>>>>>
>>>>>nrecno = recno()
>>>>>nseq = sequence
>>>>>replace all sequence with sequence*1000
>>>>>replace all sequence with sequence/1000+nseq*1000 for flag=.T.
>>>>>i=0
>>>>>scan
>>>>> i=i+1
>>>>> replace sequence with i
>>>>>endscan
>>>>>
>>>>>The scan is slow. Is it possible to do it in one replace statement?
>>>>>
>>>>>Can anyone suggest other ways of re-sequencing of records?
>>>>
>>>>Your algorithm is slow because you scan/replace all records in table. I would advise to change sequence value just for records you want to move:
>>>>Select table1 && this is Grid.Recordsource
>>>>Set order to tag sequence
>>>>Calculate min(sequence) to nMinsequence
>>>>nCounter=0
>>>>Scan For flag=.t. && have tag on flag for better performance
>>>> nCounter=nCounter+1
>>>> Replace table1.Sequence with nMinsequence-nCounter
>>>>Endscan
>>>>Thisform.Grid1.Refresh
>>>
>>>Sorry, I think there is a misunderstanding. I didn't phrase my question clear enough.
>>>
>>>My user can select any records on the grid. Then he can move all the selected records to a specific location he choose. For example, I have,
>>>
>>>seq desc Flag
>>>1 Rec1 .F.
>>>2 Rec2 .T.
>>>3 Rec3 .F.
>>>4 Rec4 .T.
>>>5 Rec5 .F.
>>>6 Rec6 .F.
>>>
>>>The users selected Rec2 & Rec4 as shown. He choose position Rec5 to move to. On 'move', I would get
>>>
>>>seq desc Flag
>>>1 Rec1 .F.
>>>2 Rec3 .F.
>>>3 Rec5 .F.
>>>4 Rec2 .T.
>>>5 Rec4 .T.
>>>6 Rec6 .F.
>>>
>>>He can also choose to move records up and ideally, he can do the kind of thing like select Rec1 & Rec5 and move them to Rec3 too.
>>>
>>>Is there a way to replace all with a running number in a faster way?
>>
>>Well, you can have additional field 'addseq' and compound tag on two fields "sequence" and "addseq". When you want to move selected records to particular place, you :
>>1. Replace all selected records sequence with 'placeholder' sequence (the same number for all these records).
>>2. Scan selected records and fill addseq value with 1,2,3... (all other records will have 0).
>>Surely, your code should be sophisticated enough to provide moving new bunch of records to the same place.
>
>Theoretically, I will get many records with the same 'placeholder' sequence and when the users want to move among the records with the same placeholder, I will come back to the same problem.
>
Theoretically yes, but practically not. As I understand user selects records by clicking on checkbox, so how many times he/she will click, especially to move to the same place, many times? Don't give your users too much freedom, or the will kill you and your application (g).