From: | Volkan YAZICI <yazicivo(at)ttnet(dot)net(dot)tr> |
---|---|
To: | JiangWei <jw(dot)pgsql(at)sduept(dot)com> |
Cc: | pgsql-interfaces(at)postgresql(dot)org |
Subject: | Re: HOWTO pass "default value" to PQexecParams? |
Date: | 2006-01-07 09:44:56 |
Message-ID: | 20060107094455.GA634@alamut |
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Thread: | |
Lists: | pgsql-interfaces |
AFAIK, it's not possible to point the field's default value using a
special value in the related array member. Because, you cannot declare
any special value in the array: NULL will be treated as NULL and other
char values as is.
(Recommended.) Why don't you omit id in the target table fields?
For instance:
sprintf(sql_cmd, "INSERT INTO test ("
(id_will_be_default) ? "" : "id, "
"name) VALUES ("
"...");
PQexecParams(conn, sql_cmd, ...);
You can also learn the default value of the related field too. (For
more information, run psql with -E parameter and type \d <table>.)
Furthermore, it's possible to define a RULE like:
ON INSERT
IF NEW.id = 0
USE DEFAULT
This will assume 0 as a reference to default value.
HTH.
Regards.
On Jan 06 09:16, JiangWei wrote:
> Create Table test (
> id int4 not null,
> name text default '<noname>'
> );
>
> PQexec (conn, "INSERT INTO test(id, name) VALUES (100,default)" ); // OK.
>
> PQexecParams (conn, "INSERT INTO test(id, name) VALUES ($1, $2)" ); //
> $1=100, $2= ????
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