Re: V8.3.0: PQprepare()/PQexecPrepared() and DECLARE CURSOR

Thank you Andrew,

I agree the example is a bit confusing, anyway it's my fault... problem fixed.

However, could you please confirm that I can use the same name for a prepared statement and a server cursor?

This seems to work:

test1=> declare s1 cursor with hold for select * from dbit2;
test1=> open s1;
test1=> prepare s1 as select * from dbit2;  -- or PQprepare ( "s1" )
test1=> execute s1;

As these are different objects for PostgreSQL - right?

Seb


Andrew Dunstan wrote:
> Sebastien FLAESCH wrote:
>> For SQL producing a result set:
>>
>>   PQprepare(... "cu1", "DECLARE cu1 CURSOR WITH HOLD ..." );
>>   PQexecPrepared( ... "cu1" ... );  -- opens the cursor...
>>   PQexec( "FETCH NEXT FROM cu1 ..." ... );
>>   PQexec( "FETCH NEXT FROM cu1 ..." ... );
>>   PQexec( "FETCH NEXT FROM cu1 ..." ... );
>>   PQexec( "CLOSE cu1" ); -- frees cursor resources (need to re-execute 
>> DECLARE)
>>   PQexecPrepared( ... "cu1" ... );  -- opens the cursor...
>>   PQexec( "FETCH NEXT FROM cu1 ..." ... );
>>   PQexec( "FETCH NEXT FROM cu1 ..." ... );
>>   PQexec( "CLOSE cu1" ); -- frees cursor resources (need to re-execute 
>> DECLARE)
>>   PQexecPrepared( ... "cu1" ... );  -- Here I get error: 
>> [42P03][cursor "cu1" already exists]
>>
>> I wonder why the second PQexecPrepare() executes and the third fails...
>>
>> To make this work, I need to de-allocate the statement and re-prepare 
>> with PQprepare() ...
>>
>> I will try to provide you with a little sample to reproduce, but 
>> wanted to post this early to let you known.
>>
> 
> This example would be clearer if you used different names for the cursor 
> and the prepared statement.
> 
> cheers
> 
> andrew
>