Обсуждение: INSERT Issues

CREATE TABLE junk ( col SERIAL PRIMARY KEY
);

INSERT INTO junk (col) DEFAULT VALUES;

INSERT INTO junk DEFAULT VALUES:


Second insert works, first one fails.

INSERT INTO table [ ( column [, ...] ) ]   { DEFAULT VALUES | VALUES ( expression [, ...] ) | SELECT query }


The column list should just be ignored correct?

--
Rod Taylor

There are always four sides to every story: your side, their side, the
truth, and what really happened.

"Rod Taylor" <rod.taylor@inquent.com> writes:
> INSERT INTO table [ ( column [, ...] ) ]
>     { DEFAULT VALUES | VALUES ( expression [, ...] ) | SELECT query }

The documentation is wrong here, not the code.  SQL92 defines the syntax
as
<insert statement> ::=     INSERT INTO <table name> <insert columns and source>
<insert columns and source> ::=     [ <left paren> <insert column list> <right paren> ] <query expression>   | DEFAULT
VALUES
<insert column list> ::= <column name list>
        regards, tom lane

create table junk (col SERIAL);

INSERT INTO junk (col) VALUES (DEFAULT);
ERROR:   parser: parse error at or near "DEFAULT";

>  INSERT INTO junk (col) VALUES (DEFAULT);
> 
> Does that work for you?
> 
> Ross
> 

On Thu, Apr 05, 2001 at 07:16:49PM -0400, Rod Taylor wrote:
> CREATE TABLE junk (
>   col SERIAL PRIMARY KEY
> );
> 
> INSERT INTO junk (col) DEFAULT VALUES;
> 
> INSERT INTO junk DEFAULT VALUES:
> 
> 
> Second insert works, first one fails.
> 
> INSERT INTO table [ ( column [, ...] ) ]
>     { DEFAULT VALUES | VALUES ( expression [, ...] ) | SELECT query }
> 
> 
> The column list should just be ignored correct?
> 

Hmm, the BNF from SQL1992 actually is:

   <insert statement> ::=          INSERT INTO <table name>             <insert columns and source>       <insert
columnsand source> ::=            [ <left paren> <insert column list> <right paren> ]            <query expression>
      | DEFAULT VALUES     <insert column list> ::= <column name list>
 

So the grammar is right to reject your first example.

According to the rules for <insert statement>:
   2) An <insert columns and source> that specifies DEFAULT VALUES is      equivalent to an <insert columns and source>
thatspecifies a      <query expression> of the form
 
        VALUES (DEFAULT, . . . )
      where the number of "DEFAULT" entries is equal to the number of      columns of T.

So the proper spelling of your first version is:
INSERT INTO junk (col) VALUES (DEFAULT);

Does that work for you?

Ross