How to test if a TConnection is active before trying to read data.
lazarus / 16-Databases

----------------------------------------------------------------------
vfclists · 2010-07-12 10:37

Is there a way of testing when a TZConnection is active when the
network is down?

The TZConnection.Connected property is true even when the network
connection is down, and it doesn't seem to change when an attempt to
connect to the database fails.

Isn't there a way of monitoring the TZConnection rather than trying to
open a table and realizing that the connection is down?

Is there also a way of trapping the exception when you try to open the
table when there is no connection? I try testing for E:EZSQLException
but it doesn't seem to catch everything.

----------------------------------------------------------------------
Mujie · 2010-07-25 16:00

Why do not you use simple logic "if else" condition ?

Code: [Select]if succeed then
begin
  //your code
else
begin
  //terminated
end;

----------------------------------------------------------------------
fredycc · 2010-07-26 01:32

Depends of your database engine you can use for example like Mujie
suggest before Execute or open datasets:

Quote  ZConnection1.Ping
              or
  ZConnection1.PingServer