Re: [HACKERS] PL/pgSQL RENAME functionality in TODOs
On Feb 1, 2007, at 5:08 AM, Pavel Stehule wrote: std. use rename only for triggers and variables new and old. It has sense. I don't see sense for rename in clasic plpgsql functions. There was one reason, rename unnamed $params. But currently plpgsql support named params and this reason is obsolete. Unless things have changed it can be a real PITA to deal with plpgsql variables that share the same name as a field in a table. IIRC there's some cases where it's not even possible to unambiguously refer to the plpgsql variable instead of the field. For internal variables there's a decent work-around... just prefix all variables with something like v_. But that's pretty ugly for parameters... get_user(user_id int) is certainly a nicer interface than get_user(p_user_id int). But I think a way to get around that would be to RENAME the arguments in the DECLARE section, so user_id could become p_user_id under the covers. So perhaps there is still a point to RENAME after-all, at least for paramaters. -- Jim Nasby[EMAIL PROTECTED] EnterpriseDB http://enterprisedb.com 512.569.9461 (cell) ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [HACKERS] PL/pgSQL RENAME functionality in TODOs
But I think a way to get around that would be to RENAME the arguments in the DECLARE section, so user_id could become p_user_id under the covers. It's one case. But I don't belive so result will be more readable. Better solution is using names qualificated by function name. I am not sure if plpgsql support it. I thing so Oracle support it and SQL/PSM support it too. like: create or replace function fx(a integer, b integer) returns void as $$ declare la integer, lb integer; begin select into la, lb tab.a, tab.b from tab where tab.a = fx.a and tab.b = fx.b I am sorry. I don't belive so using RENAME is better So perhaps there is still a point to RENAME after-all, at least for paramaters. -- Jim Nasby[EMAIL PROTECTED] EnterpriseDB http://enterprisedb.com 512.569.9461 (cell) Pavel Stehule _ Najdete si svou lasku a nove pratele na Match.com. http://www.msn.cz/ ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
Re: [HACKERS] PL/pgSQL RENAME functionality in TODOs
On 2/2/07, Jim Nasby [EMAIL PROTECTED] wrote: On Feb 1, 2007, at 5:08 AM, Pavel Stehule wrote: std. use rename only for triggers and variables new and old. It has sense. I don't see sense for rename in clasic plpgsql functions. There was one reason, rename unnamed $params. But currently plpgsql support named params and this reason is obsolete. Unless things have changed it can be a real PITA to deal with plpgsql variables that share the same name as a field in a table. IIRC there's some cases where it's not even possible to unambiguously refer to the plpgsql variable instead of the field. For internal variables there's a decent work-around... just prefix all variables with something like v_. But that's pretty ugly for parameters... get_user(user_id int) is certainly a nicer interface than get_user(p_user_id int). But I think a way to get around that would be to RENAME the arguments in the DECLARE section, so user_id could become p_user_id under the covers. So perhaps there is still a point to RENAME after-all, at least for paramaters. -- Jim Nasby[EMAIL PROTECTED] EnterpriseDB http://enterprisedb.com 512.569.9461 (cell) Parameters can be renamed in 8.2. The only thing which does not work is renaming a variable immediately after its declaration which is a useless functionality. So, should we still consider it a ToDo? -- Imad www.EnterpriseDB.com ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
Re: [HACKERS] PL/pgSQL RENAME functionality in TODOs
imad [EMAIL PROTECTED] writes: So, should we still consider it a ToDo? Whatever you think about the rename-in-same-block-as-declared case, it's still broken, as per my example showing that the effects are not limited to the containing block. However, considering that no one has taken an interest in fixing it since 7.2, it's obviously not a high-priority feature. regards, tom lane ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [HACKERS] PL/pgSQL RENAME functionality in TODOs
On 2/1/07, Tom Lane [EMAIL PROTECTED] wrote: imad [EMAIL PROTECTED] writes: OK, so renaming does not work in the same block. You can rename a vairable in a nested block and thats why it works for OLD/NEW. BTW, what is the purpose behind it? Declaring a variable in a block and quickly renaming it does not make sense to me. I agree it's pretty useless; but if we're gonna forbid it then we should throw a more sensible error than syntax error. Actually, it seems to me that it works in the nested-block case only for rather small values of work: regression=# create function foo() returns int as $$ regression$# declare regression$# x int := 1; regression$# begin regression$# x := 2; regression$# declare regression$# rename x to y; regression$# begin regression$#y := 3; regression$# end; regression$# return x; regression$# end$$ language plpgsql; CREATE FUNCTION regression=# select foo(); ERROR: column x does not exist LINE 1: SELECT x ^ QUERY: SELECT x CONTEXT: PL/pgSQL function foo line 10 at return regression=# Surely the variable's name should be x again after we're out of the nested block? Yes, seems to be the only possible reason of renaming a variable. --Imad www.EnterpriseDB.com ---(end of broadcast)--- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
Re: [HACKERS] PL/pgSQL RENAME functionality in TODOs
Hello, std. use rename only for triggers and variables new and old. It has sense. I don't see sense for rename in clasic plpgsql functions. There was one reason, rename unnamed $params. But currently plpgsql support named params and this reason is obsolete. Regards Pavel Stehule _ Emotikony a pozadi programu MSN Messenger ozivi vasi konverzaci. http://messenger.msn.cz/ ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [HACKERS] PL/pgSQL RENAME functionality in TODOs
imad [EMAIL PROTECTED] writes: OK, so renaming does not work in the same block. You can rename a vairable in a nested block and thats why it works for OLD/NEW. BTW, what is the purpose behind it? Declaring a variable in a block and quickly renaming it does not make sense to me. I agree it's pretty useless; but if we're gonna forbid it then we should throw a more sensible error than syntax error. Actually, it seems to me that it works in the nested-block case only for rather small values of work: regression=# create function foo() returns int as $$ regression$# declare regression$# x int := 1; regression$# begin regression$# x := 2; regression$# declare regression$# rename x to y; regression$# begin regression$#y := 3; regression$# end; regression$# return x; regression$# end$$ language plpgsql; CREATE FUNCTION regression=# select foo(); ERROR: column x does not exist LINE 1: SELECT x ^ QUERY: SELECT x CONTEXT: PL/pgSQL function foo line 10 at return regression=# Surely the variable's name should be x again after we're out of the nested block? regards, tom lane ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
Re: [HACKERS] PL/pgSQL RENAME functionality in TODOs
imad [EMAIL PROTECTED] writes: Fix RENAME to work on variables other than OLD/NEW I can rename just any variable declared in a PL block apart from OLD/NEW. Is the TODOs list out of sync or I am missing the point here? Really? It looks pretty broken to me still: regression=# create function foo() returns int as $$ regression$# declare regression$# x int := 1; regression$# rename x to y; regression$# begin regression$# return y; regression$# end;$$ language plpgsql; ERROR: syntax error at or near x LINE 4: rename x to y; ^ See old discussion here: http://archives.postgresql.org/pgsql-hackers/2002-03/msg00591.php regards, tom lane ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [HACKERS] PL/pgSQL RENAME functionality in TODOs
URL added to TODO. (I didn't have URLs in there at the time). --- Tom Lane wrote: imad [EMAIL PROTECTED] writes: Fix RENAME to work on variables other than OLD/NEW I can rename just any variable declared in a PL block apart from OLD/NEW. Is the TODOs list out of sync or I am missing the point here? Really? It looks pretty broken to me still: regression=# create function foo() returns int as $$ regression$# declare regression$# x int := 1; regression$# rename x to y; regression$# begin regression$# return y; regression$# end;$$ language plpgsql; ERROR: syntax error at or near x LINE 4: rename x to y; ^ See old discussion here: http://archives.postgresql.org/pgsql-hackers/2002-03/msg00591.php regards, tom lane ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly -- Bruce Momjian [EMAIL PROTECTED] EnterpriseDBhttp://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [HACKERS] PL/pgSQL RENAME functionality in TODOs
OK, so renaming does not work in the same block. You can rename a vairable in a nested block and thats why it works for OLD/NEW. BTW, what is the purpose behind it? Declaring a variable in a block and quickly renaming it does not make sense to me. --Imad www.EnterpriseDB.com On 1/31/07, Bruce Momjian [EMAIL PROTECTED] wrote: URL added to TODO. (I didn't have URLs in there at the time). --- Tom Lane wrote: imad [EMAIL PROTECTED] writes: Fix RENAME to work on variables other than OLD/NEW I can rename just any variable declared in a PL block apart from OLD/NEW. Is the TODOs list out of sync or I am missing the point here? Really? It looks pretty broken to me still: regression=# create function foo() returns int as $$ regression$# declare regression$# x int := 1; regression$# rename x to y; regression$# begin regression$# return y; regression$# end;$$ language plpgsql; ERROR: syntax error at or near x LINE 4: rename x to y; ^ See old discussion here: http://archives.postgresql.org/pgsql-hackers/2002-03/msg00591.php regards, tom lane ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly -- Bruce Momjian [EMAIL PROTECTED] EnterpriseDBhttp://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---(end of broadcast)--- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
