Re: [SQL] WITH RECURSION output ordering with trees

2009-07-10 Thread Philippe Lang
pgsql-sql-ow...@postgresql.org wrote: > In article > , > "Philippe Lang" writes: > >> Thanks for your answer. Si there a built-in function that would allow >> generating the sort path based on the value of the lookup column, >> instead of the id, which has no meaning at all? > >> If yes, we wou

Re: [SQL] WITH RECURSION output ordering with trees

2009-07-10 Thread Harald Fuchs
In article , "Philippe Lang" writes: > Thanks for your answer. Si there a built-in function that would allow > generating the sort path based on the value of the lookup column, > instead of the id, which has no meaning at all? > If yes, we would get instead: > depth | id | lookup | parent_id

Re: [SQL] WITH RECURSION output ordering with trees

2009-07-10 Thread Philippe Lang
pgsql-sql-ow...@postgresql.org wrote: > Philippe Lang, 10.07.2009 11:10: >> Hi, >> >> I'm playing with the new "WITH RECURSIVE" feature of 8.4. I'm trying >> to figure out how to use it with trees. >> >> Here is the test code I use: >> >> I'd like to perform a real recursion, and show the tree s

Re: [SQL] WITH RECURSION output ordering with trees

2009-07-10 Thread Thomas Kellerer
Philippe Lang, 10.07.2009 11:10: Hi, I'm playing with the new "WITH RECURSIVE" feature of 8.4. I'm trying to figure out how to use it with trees. Here is the test code I use: I'd like to perform a real recursion, and show the tree structure in a more appopriate way, like this: Any idea how to

Re: [SQL] WITH RECURSION output ordering with trees

2009-07-10 Thread Philippe Lang
pgsql-sql-ow...@postgresql.org wrote: > Hi, > > I'm playing with the new "WITH RECURSIVE" feature of 8.4. I'm trying > to figure out how to use it with trees. > > Here is the test code I use: > > - > --DROP TABLE recursion; > > CREATE TAB

[SQL] WITH RECURSION output ordering with trees

2009-07-10 Thread Philippe Lang
Hi, I'm playing with the new "WITH RECURSIVE" feature of 8.4. I'm trying to figure out how to use it with trees. Here is the test code I use: - --DROP TABLE recursion; CREATE TABLE recursion ( id serial, lookup varchar(16), parent_id

Re: [SQL] How update a table within a join efficiently ?

2009-07-10 Thread Pavel Stehule
2009/7/10 Andreas : > Hi, > how would I update a table within a join in a more efficient way? > > E.g. the folowing case: > table_a holds abstract elements. One column represents "priority" which can > be based on information of other tables. > table_b might hold such details in a column "size" for

[SQL] How update a table within a join efficiently ?

2009-07-10 Thread Andreas
Hi, how would I update a table within a join in a more efficient way? E.g. the folowing case: table_a holds abstract elements. One column represents "priority" which can be based on information of other tables. table_b might hold such details in a column "size" for about 3000 of 8 records o

Re: [SQL] skip if latter value equal

2009-07-10 Thread Marcin Krawczyk
Thanks a lot. pozdrowienia mk 2009/7/10 Pavel Stehule > Hello > > you can do it simply in new PostgreSQL 8.4. In older version the best > way what I know is using a stored procedure, that returns table > > create or replace function foo() > returns setof yourtablename as $$ > declare > r your

Re: [SQL] skip if latter value equal

2009-07-10 Thread Pavel Stehule
Hello you can do it simply in new PostgreSQL 8.4. In older version the best way what I know is using a stored procedure, that returns table create or replace function foo() returns setof yourtablename as $$ declare r yourtablename; s yourtablename; result youratblename; first boolean = tr

[SQL] skip if latter value equal

2009-07-10 Thread Marcin Krawczyk
Hi list, I was wondering if it was possible for a field in SQL query to return NULL if latter value is exactly the same ? - for given ORDER BY clause, I guess. For example, query returns: xxyy 1 4 true xxyy 5 7 true xxyy 21 8 true yyzz 5 1 false yyzz 7 7 false yyzz 8 34 false I'd