Updating a table column using LIKE in WHERE - sql

Question

I have a table(ENTITY) that needs to be updated based on an ID(FUNNCODE) but the ID(FUNNCODE) is linked between two other tables(from JOINT then to POSITION)
and is independent of where the data is at(table NEORSD). The only parameter I can bind is the position name between the NEORSD table and POSITION table. When I place my LIKE statement into the where clause I get an error in return. If anyone can point me in the right direction it would be greatly appreciated!
Tables:
NEORSD: Contains the range information and 'position name(= Tag_No)'
ENTITY: Needs to update and accept the range information (Holds FUNCCODE)
JOINT: Holds FUNCCODE(named POSFUNCCODE) and corresponding POSCODE
POSITION: Contains POSCODE and 'position name(=POSID)'
UPDATE ENTITY
SET
RANGE0 = (
SELECT RANGE0
FROM NEORSD_1199
WHERE Tag_No like ('%PIT%'))
WHERE
FUNCCODE = (
SELECT POSFUNCCODE
FROM JOINT
WHERE POSCODE = (
SELECT POSCODE
FROM POSITION
WHERE POSID like ('%PIT%'))

Answer 1

If NEORSD_1199 has more than one row with a tag_no like '%PIT%', which NEORSD_1199.RANGE0 value should it use to update ENTITY.RANGE0?
This is the db engine's problem with your SQL.
To better understand, read the SQL backwards:
First you're getting a list of every Position Code from the POSITION table where the Position ID is like '%PIT%'. That might be one code, and it might be one hundred codes.
Then you're getting every Position Function Code from the JOINT table where the Position Code is in the list of Position Codes you just gathered. Again, could be one, could be a hundred.
Then you're getting a list of all values of RANGE0 from the NEORSD1199 table where Tag_No is like '%PIT%'. Again, this could be one value, or a list of one hundred.
Then, you're getting every row from the ENTITY table where the Function Code is in the list of Position Function Codes you gathered from the JOINT table (step 2 above), and you're updating RANGE0 in each of these rows to the value you captured in step 3.
The problem is that the 'value' returned in step 3 could be a list of values. If
NEORSD1199 has four rows where tag number is like '%PIT%'
(e.g. PIT01,PIT02,PIT03,APIT00), and each of those rows has a different
RANGE0 (e.g. 1,2,3,99), then which of those four values should the DB engine use to update RANGE0 in the rows in the ENTITY table?

Answer 2

Thank you to #SQLCliff for the questions that help to find the solution. I created an ID column inside my NEORSD table, created a temporary table holding the link between FUNCCODE and the ranges in NEORSD. Then I updated ENTITY using a join on. I can insert the where clause at the end of the temporary table for filtering if needed. Since it is a mass update I no longer require a where clause. My brain just likes making things more complicated than they need to be XD
with t as(
select f.funccode as funccode ,n.range0, n.range100
from func as f
join NEORSD_1199_With_Ranges_Updated as n on n.id = f.poscode or n.id =f.devcode
/* WHERE nessecrary ;P*/)
update entity
set
range0 = t.range0,
range100 = t.range100
from entity as e
join t on e.funccode = t.funccode