cMax 1

[novice001]

Hello All,
I need to find maximum value in one of the fields of the table. I open it using tCursor, and use cMax to get the maximum:

tcData.open(":data:table&quot
tcData.edit()
nuValue = tcData.cMax("field 1&quot

It works fine, however, i'm afraid this can fail in multiuser environment, because cMax requires full lock on the table. Is there any alternative to this function?
Thank you

 

[footpad]

novice001,

You are correct, cMax() requires exclusive access for an accurate result, which pretty much limits its use in a multi-user situation to private answer tables or cloned cursors. You do have several options to choose from:

1. Walk through the table, e.g:

tcData.open(":data:table")
nuValue = 0
scan tcData : 
   nuValue = nuValue + tcData."field 1"
endScan
tcData.close()

2. Use a QBE query:

nuValue = 0
qryMax = QUERY

   :DATA:TABLE | FIELD 1      |
               | CALC MAX ALL |

endQuery
if not qbeMax.execute( tcAnswer ) then
   errorShow( "Query Problem", "See [>>] for details..." )
else
   nuValue = tcAnswer.(1)
endIf
return nuValue

3. Use a SQL query (similar to the above, only you replace the QBE variable with a SQL variable populated with appropriate syntax.

4. Make a temporay copy of the current table in the user's RIV: folder and then cMax() that.

5. Drop a hidden, calculated field on your form, make sure all edits are posted, assign it as a Max() summary field, and then grab the

Value

property at run-time.

Each of these offers certain benefits and disavantages for various situations. Hopefully, one of them will work for your needs.

Hope this helps...

-- Lance