Directly embedding a psql SET variable inside another string?
Pg 12
I need to pass a \set variable (in this example named v_ssn) into a LIKE
string. A two-stage process (building v_like from v_ssn, and then using
v_like in the LIKE string) works, and is fine when executing an sql script,
but not so good is there any way to *directly* embed v_ssn in another string?
test=# \set v_ssn 345
test=# \echo :v_ssn
345
test=# \set v_like %:v_ssn%
test=# \echo :v_like
%345%
test=# SELECT * FROM employee WHERE ssn LIKE :'v_like';
ssn | name | ssn_int
-----------+----------+-----------
123456789 | John Doe | 123456789
(1 row)
As expected, this fails:
postgres=# SELECT * FROM employee WHERE ssn LIKE :'%v_ssn%';
ERROR: syntax error at or near ":"
LINE 1: SELECT * FROM employee WHERE ssn LIKE :'%v_ssn%';
--
Born in Arizona, moved to Babylonia.
Do you mean like this?
postgres=# \set v_embed %:v_ssn%
postgres=# \echo :v_embed
%345%
postgres=# SELECT * FROM employee WHERE ssn LIKE :'v_embed';
ssn | name
-----------+----------
123456789 | John Doe
(1 row)
On Fri, Jan 13, 2023 at 8:12 AM Ron <ronljohnsonjr@gmail.com> wrote:
Show quoted text
Pg 12
I need to pass a \set variable (in this example named v_ssn) into a LIKE
string. A two-stage process (building v_like from v_ssn, and then using
v_like in the LIKE string) works, and is fine when executing an sql script,
but not so good is there any way to *directly* embed v_ssn in another
string?test=# \set v_ssn 345
test=# \echo :v_ssn
345
test=# \set v_like %:v_ssn%
test=# \echo :v_like
%345%test=# SELECT * FROM employee WHERE ssn LIKE :'v_like';
ssn | name | ssn_int
-----------+----------+-----------
123456789 | John Doe | 123456789
(1 row)As expected, this fails:
postgres=# SELECT * FROM employee WHERE ssn LIKE :'%v_ssn%';
ERROR: syntax error at or near ":"
LINE 1: SELECT * FROM employee WHERE ssn LIKE :'%v_ssn%';--
Born in Arizona, moved to Babylonia.
On Fri, Jan 13, 2023 at 9:12 AM Ron <ronljohnsonjr@gmail.com> wrote:
is there any way to *directly* embed v_ssn in another string?
No
As expected, this fails:
postgres=# SELECT * FROM employee WHERE ssn LIKE :'%v_ssn%';
ERROR: syntax error at or near ":"
LINE 1: SELECT * FROM employee WHERE ssn LIKE :'%v_ssn%';
Two options:
format('%%%s%%', :'v_ssn')
'%' || :'v_ssn' || '%'
David J.
On 1/13/23 09:08, Adam Scott wrote:
Do you mean like this?
postgres=# \set v_embed %:v_ssn%
postgres=# \echo :v_embed
%345%
postgres=# SELECT * FROM employee WHERE ssn LIKE :'v_embed';
ssn | name
-----------+----------
123456789 | John Doe
(1 row)
Actually that replicates what Ron got to work. What Ron is looking for
is to skip the intermediate step and do:
\set v_ssn 345
SELECT * FROM employee WHERE ssn LIKE :'%v_ssn%';
--
Adrian Klaver
adrian.klaver@aklaver.com
Please don't top-post.
On Fri, Jan 13, 2023 at 10:08 AM Adam Scott <adam.c.scott@gmail.com> wrote:
Do you mean like this?
postgres=# \set v_embed %:v_ssn%
postgres=# \echo :v_embed
test=# \set v_like %:v_ssn%
test=# \echo :v_like
Aside from the names those look identical...
David J.
On 1/13/23 11:13, David G. Johnston wrote:
On Fri, Jan 13, 2023 at 9:12 AM Ron <ronljohnsonjr@gmail.com> wrote:
is there any way to *directly* embed v_ssn in another string?
No
As expected, this fails:postgres=# SELECT * FROM employee WHERE ssn LIKE :'%v_ssn%';
ERROR: syntax error at or near ":"
LINE 1: SELECT * FROM employee WHERE ssn LIKE :'%v_ssn%';Two options:
format('%%%s%%', :'v_ssn')
This one looks clean, and works perfectly:
'%' || :'v_ssn' || '%'
--
Born in Arizona, moved to Babylonia.