PREPARE vs query with MULTIPLE statements
Hello.
I have found an interesting FRONTEND/BACKEND protocol behaviour. Let's
consider following query:
"SELECT 1; SELECT 2; SELECT3; SELECT4;"
1) If I send it as a simple query - I'm getting:
- correct results for SELECT 1; SELECT 2; SELECT3; SELECT4;
- and then one ReadyForQuery response
from backend.
[send_simple.log & recv_simple.log]
2) If I send it as 'PREPARE "SQL_CUR1" AS SELECT 1; SELECT 2; SELECT3;
SELECT4;' and then 'EXECUTE "SQL_CUR1" - I'm getting:
- results for SELECT 1; SELECT2; SELECT 3;
- ReadyForQuery response
- results for SELECT 4;
- one more ReadyForQuery response
from backend
[send_prepared.log & recv_prepared.log]
Is this behavour is correct and expected?
P.s. Tested on Windows with PostgreSQL 8.0, 8.1 and 8.2 with the same
results.
Thank You,
Andrei.
Attachments:
send_prepare.logtext/plain; name=send_prepare.logDownload
# user andrei database test p (md5******************************** Q %SET client_encoding to 'UNICODE' Q SELECT version() Q =PREPARE"SQL_CUR1"AS SELECT 1;SELECT 2;SELECT 3;SELECT 4; Q EXECUTE"SQL_CUR1" send_simple.logtext/plain; name=send_simple.logDownload
# user andrei database test p (md5******************************** Q %SET client_encoding to 'UNICODE' Q SELECT version() Q )SELECT 1;SELECT 2;SELECT 3;SELECT 4; 
Andrei Kovalevski <andyk@commandprompt.com> writes:
2) If I send it as 'PREPARE "SQL_CUR1" AS SELECT 1; SELECT 2; SELECT3;
SELECT4;' and then 'EXECUTE "SQL_CUR1" - I'm getting:
- results for SELECT 1; SELECT2; SELECT 3;
- ReadyForQuery response
- results for SELECT 4;
- one more ReadyForQuery response
from backend
Is this behavour is correct and expected?
You seem to have some odd ideas about what the semicolons mean.
The prepare command there is PREPARE "SQL_CUR1" AS SELECT 1
... no more and no less.
regards, tom lane
Yes, Thank you!
Tom Lane wrote:
Show quoted text
Andrei Kovalevski <andyk@commandprompt.com> writes:
2) If I send it as 'PREPARE "SQL_CUR1" AS SELECT 1; SELECT 2; SELECT3;
SELECT4;' and then 'EXECUTE "SQL_CUR1" - I'm getting:
- results for SELECT 1; SELECT2; SELECT 3;
- ReadyForQuery response
- results for SELECT 4;
- one more ReadyForQuery response
from backendIs this behavour is correct and expected?
You seem to have some odd ideas about what the semicolons mean.
The prepare command there is PREPARE "SQL_CUR1" AS SELECT 1
... no more and no less.regards, tom lane
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