Re: Concatenate table name in Pl/Pgsql - Mailing list pgsql-general

From Adarsh Sharma
Subject Re: Concatenate table name in Pl/Pgsql
Date
Msg-id CAGx-QqLa+nFOtw7148h6RV4Jv4nwh8+JZpumnoFSoiOUUXDmtA@mail.gmail.com
Whole thread Raw
In response to Re: Concatenate table name in Pl/Pgsql  (Adarsh Sharma <eddy.adarsh@gmail.com>)
List pgsql-general
Final Fix :

 execute 'insert into tmp'||abc||  ' select  $1.*' using new; 

Thanks


On Wed, Jun 26, 2013 at 12:18 PM, Adarsh Sharma <eddy.adarsh@gmail.com> wrote:
Able to fix but still new error :(


test=# CREATE OR REPLACE FUNCTION tmp_trigger_function()
test-# RETURNS TRIGGER AS $$
test$# DECLARE
test$# stmt text;
test$# abc varchar;
test$# BEGIN
test$# select to_char(NEW.a::timestamp,'yyyymmdd') into abc ;
test$# stmt := 'insert into tmp'||abc||  ' values ' ||   NEW.* ;
test$# EXECUTE stmt;

test$# RETURN NULL;
test$# END;
test$# $$
test-# LANGUAGE plpgsql;
CREATE FUNCTION
Time: 0.996 ms
test=# insert into tmp values ('2013-06-02','Start','process');
ERROR:  column "2013-06-02 00:00:00" does not exist
LINE 1: insert into tmp20130602 values ("2013-06-02 00:00:00",Start,...
                                        ^
QUERY:  insert into tmp20130602 values ("2013-06-02 00:00:00",Start,process)
CONTEXT:  PL/pgSQL function tmp_trigger_function() line 8 at EXECUTE statement


On Wed, Jun 26, 2013 at 11:26 AM, Adarsh Sharma <eddy.adarsh@gmail.com> wrote:
Passing each column seems not good because if column additon/deletion happens in future , we also need to change function as well. I think below will work :-


test=# CREATE OR REPLACE FUNCTION tmp_trigger_function()
test-# RETURNS TRIGGER AS $$
test$# DECLARE
test$# abc varchar;
test$# BEGIN
test$# select to_char(NEW.a::timestamp,'yyyymmdd') into abc ;
test$# EXECUTE 'insert into tmp'||abc||  ' values ' ||  '( NEW.* )';

test$# RETURN NULL;
test$# END;
test$# $$
test-# LANGUAGE plpgsql;
CREATE FUNCTION
Time: 0.913 ms
test=# insert into tmp values ('Tom','2013-06-03');
ERROR:  missing FROM-clause entry for table "new"
LINE 1: insert into tmp20130603 values ( NEW.* )
                                         ^
QUERY:  insert into tmp20130603 values ( NEW.* )
CONTEXT:  PL/pgSQL function tmp_trigger_function() line 6 at EXECUTE statement
Time: 0.749 ms
test=#

But don't understand why it is taking NEW as table. Clearly shows table name is concatenated but data insertion fails :(

Thanks


On Wed, Jun 26, 2013 at 11:14 AM, Ian Lawrence Barwick <barwick@gmail.com> wrote:
> Thanks
>
>
> On Wed, Jun 26, 2013 at 10:52 AM, Ian Lawrence Barwick <barwick@gmail.com>
> wrote:
>>
>> 2013/6/26 Adarsh Sharma <eddy.adarsh@gmail.com>:
>> > Hi ,
>> >
>> > Today i m creating a function that includes dynamic concatenation of a
>> > partitioned table name as below :-
>> >
>> > test=# CREATE OR REPLACE FUNCTION tmp_trigger_function()
>> > test-# RETURNS TRIGGER AS $$
>> > test$# DECLARE
>> > test$# tbl_name text;
>> > test$# abc varchar;
>> > test$# BEGIN
>> > test$# tbl_name := 'tmp';
>> > test$# select to_char(NEW.a::timestamp,'yyyymmdd') into abc ;
>> > test$# insert into tmp || abc values ( NEW.* );
>> > test$# RETURN NULL;
>> > test$# END;
>> > test$# $$
>> > test-# LANGUAGE plpgsql;
>> > ERROR:  syntax error at or near "||"
>> > LINE 9: insert into tmp || abc values ( NEW.* );
>> >                         ^
>> > Time: 0.901 ms
>> > test=#
>> > test=#
>> >
>> > I tried with a statement variable also. Any ideas ?
>>
>> You'll need to create a string and use EXECUTE, something along the lines
>> of:
>>
>> stmt := 'insert into ' || tmp || abc || ' VALUES ($1)'
>> EXECUTE stmt USING NEW.*;
>>
>>
>> http://www.postgresql.org/docs/current/interactive/plpgsql-statements.html#PLPGSQL-STATEMENTS-EXECUTING-DYN


2013/6/26 Adarsh Sharma <eddy.adarsh@gmail.com>:
> Thanks Ian for such a quick response. But my NEW.* will be 10-15 columns
> row.
>
>
> test=# CREATE OR REPLACE FUNCTION tmp_trigger_function()
> test-# RETURNS TRIGGER AS $$
> test$# DECLARE
> test$# stmt text;
>
> test$# abc varchar;
> test$# BEGIN
> test$# select to_char(NEW.a::timestamp,'yyyymmdd') into abc ;
> test$# stmt := 'insert into ' || tmp || abc || ' VALUES ($1)'
> test$# EXECUTE stmt USING NEW.*;
>
> test$# RETURN NULL;
> test$# END;
> test$# $$
> test-# LANGUAGE plpgsql;
> ERROR:  syntax error at or near "EXECUTE"
> LINE 9: EXECUTE stmt USING NEW.*;
>         ^
> Time: 0.737 ms
> test=#

You'll need to specify each column explicitly if there's more than one.

Regards

Ian Barwick



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