Re: Uniform UPDATE queries

On Fri, 2012-04-13 at 20:42 +0200, Dennis wrote:
> When a query is written to update a table, the usual process is to list all the columns that need 
> updating. This could imply the creation of many possible queries for many columns. In an effort to 
> keep the UPDATE queries more uniform, less number of unique queries, a keyword similar to DEFAULT, 
> let's say CURRENT, is required to indicate that the current value must not change.
> 
> Examples:
> 
> update mytable set ( d ) = ("newvalue")
> 
> This is the usual way to change values in column "d" and requires writing a new query for updating 
> every column.
> 
> update mytable set ( a, b, c, d ) = ( a, b, c, "newvalue" )
> 
> This sort of works to change only column "d", but requires explicit naming of the columns on the 
> value side.
> 
> My suggestion is to introduce the CURRENT keyword:
> 
> update mytable set ( a, b, c, d ) = ( CURRENT, CURRENT, CURRENT, "newvalue" )
> 
> This could then lead to the uniform prepared JDBC statement:
> 
> update mytable set ( a, b, c, d ) = ( ?, ?, ?, ? ) where id = ( ? );
> 
> And then the JDBC driver could be improved to accept stmt.setString( 4, "newvalue" ) and 
> automagically substitute the first three parameters with CURRENT when the query is executed. Note 
> the added WHERE clause? The parameter for id is always on the same index. This makes the bookkeeping 
> a lot easier and should reduce the need for generating UPDATE queries or even client JDBC code.
> 

I guess you didn't send it to the right mailing list. This list is about
pgAdmin support.


-- 
Guillaume
http://blog.guillaume.lelarge.info
http://www.dalibo.com