PSQL: Concatenate a value with LIKE in stored procedure - sql

Question

I am trying to concatenate a variable using the LIKE statement and for some reason it only finds values where the word to search is at the end of the text variable.
I am using PostgreSQL 8.4 and this is stored in a function (stored procedure)
considering in this example:
a.key1 is "HELLO"
a_text is "I SAY HELLO TO THE WORLD"
Code:
SELECT count(1), a.key1, a.active, a.campkeydbid
FROM campkeydb a
WHERE a_text LIKE '%'|| a.key1 ||'%'
GROUP BY a.key1, a.active, a.campkeydbid
INTO a_count, a_campaignkey, a_active, a_campkeydbid;
In this stored procedure it will NOT return the values; it will not find the word "HELLO"?
It will ONLY return the values if a_text contains "I SAY HELLO"
Does anyone knows what I am doing wrong? It seems that it is correct as I am concatenating a % on both sides of the variable a.key1.

Answer 1

You can use the position string function instead of like. Here is a sample query using a table of the regions and departments of France. I'll try and find all the departments that have a name that includes the region name.
select r.name as region, d.name as deprtment, position( r.name in d.name) as pos
from regions r
join departments d on d.region = r.code
where position( r.name in d.name) != 0
and r.name != d.name;
The results are
region department pos
"Corse" "Corse-du-Sud" 1
"Corse" "Haute-Corse" 7
I added the pos column to show that strings are indexed from 1, not 0. I tried the same thing with 'like' (both queries have the same query plan and should give the same performance):
select r.name as region, d.name as deprtment, position( r.name in d.name) as pos
from regions r
join departments d on d.region = r.code
where d.name like '%' || r.name || '%'
and r.name != d.name;
I like the appearance of the first query, but they both do the same thing. So your logic seems correct, so this seems like a typo in a string.