SQL Server using the REPLACE function to replace values in a column spanning multiple rows - sql

Question

I have a table like this:
Rule | Mask |Replacement
---------------------------------
# # 12 | # |[^0-9]
# # 12 | # |[0-9]
That I constructed joining these two tables
Table 1
Mask_ID | Mask |Replacement
---------------------------------
1 | # |[^0-9]
2 | # |[0-9]
Table 2
Rule_ID | Rule
--------------
1 | # # 12
The result I want is this:
Rule | Expression
--------------------
# # 12 | [^0-9] [0-9] 12
I've been trying to use the REPLACE button to do this, but I've only been able to generate this result
Rule | Expression
--------------------
# # 12 | [^0-9] # 12
# # 12 | # [0-9] 12
I'm not sure how to get the REPLACE function to apply multiple rows to a single row. If anyone has any suggestions, I would appreciate it.
This is what I have so far, but its causing me to get the result I mentioned above:
SELECT
A.PointMask_CODE
,B.PointMasking_Rule_CODE
,B.Mask
,B.Escape_Character
,B.EscapedMaskRule
,REPLACE(A.PointMask_CODE, B.Mask, B.EscapedMaskRule)
FROM
tblStatusPointMasks_CORE A
LEFT JOIN
vwAORs_Status_PointMasks_EscapedRules B
ON
PointMask_CODE LIKE '%' + B.EscapedMask + '%' ESCAPE ISNULL(B.Escape_Character, '\')

Answer 1

For your given sample data, you could use a recursive common table expression (cte).
create table masks (mask_id int, mask varchar(32), replacement varchar(32));
insert into masks values
(1, '#', '[^0-9]')
,(2, '#', '[0-9]');
create table rules (rule_id int, rule_txt varchar(32));
insert into rules values
(1, '# # 12');
with cte as (
select
r.rule_id
, r.rule_txt
, masks = 0
from rules r
union all
select
r.rule_id
, rule_txt = convert(varchar(32),replace(r.rule_txt,m.mask,m.replacement))
, masks = r.masks+1
from masks m
inner join cte r
on r.rule_txt like '%'+m.mask+'%'
)
select top 1 *
from cte
order by masks desc
rextester demo: http://rextester.com/KAV58392
returns:
+---------+-----------------+-------+
| rule_id | rule_txt | masks |
+---------+-----------------+-------+
| 1 | [^0-9] [0-9] 12 | 2 |
+---------+-----------------+-------+

Answer 2

One more option, using string operations...
create table masks (mask_id int, mask varchar(32), replacement varchar(32));
insert into masks values
(1, '#', '[^0-9]')
,(2, '#', '[0-9]');
create table rules (rule_id int, rule_txt varchar(32));
insert into rules values
(1, '# # # # 12');
declare #Table Table (charval varchar(10))
declare #char varchar(10), #rule_txt varchar(50)
select #rule_txt=rule_txt FROM rules
while charindex(' ',#rule_txt)>0
begin
select #char=substring(#rule_txt,1,charindex(' ',#rule_txt)-1)
FROM rules
insert into #Table values (#char)
SET #rule_txt=RIGHT(#rule_txt,(len(#rule_txt)-charindex(' ',#rule_txt)))
END
insert into #Table values (#rule_txt)
select stuff((SELECT ' '+isnull(replacement,charval)
from #Table T left join masks M on M.mask=T.charval
for xml path('')),1,1,'')
drop table rules
drop table masks