How to update sql column based on matching special character - tsql

I'm trying to get rid of some bad characters in our database. The rows I'm working on at the moment start with a bullet and a space. My where clause isn't matching the rows in question, however. How can I get a match? This is what I'm currently trying.
update Skill
set Name = substring(Name, 3, 50)
where Name like char(150) + ' %'

Perhaps you aren't capturing the correct ASCII value. Here's a way with unicode that uses a similar method.
declare #table table ([Name] nvarchar(64))
insert into #table
values
('- some data')
select
UNICODE(left([Name],1)) --this will tell you what VALUE to use in the where clause
,NCHAR(UNICODE(left([Name],1)))
from #table
update #table
set [Name] = substring([Name], 3, 50)
where UNICODE(left([Name],1)) = 45 --use the appropriate UNICODE values here
select * from #table

As stated in the comments you can use ASCII() to get the code for the character you are looking for and then use that code in your update.
UPDATE Skill
set Name = substring(Name, 3, 50)
WHERE LEFT(name,1) = CHAR(149)

Related

PGSQL - How to efficiently flatten key/value table [duplicate]

Does any one know how to create crosstab queries in PostgreSQL?
For example I have the following table:
Section Status Count
A Active 1
A Inactive 2
B Active 4
B Inactive 5
I would like the query to return the following crosstab:
Section Active Inactive
A 1 2
B 4 5
Is this possible?
Install the additional module tablefunc once per database, which provides the function crosstab(). Since Postgres 9.1 you can use CREATE EXTENSION for that:
CREATE EXTENSION IF NOT EXISTS tablefunc;
Improved test case
CREATE TABLE tbl (
section text
, status text
, ct integer -- "count" is a reserved word in standard SQL
);
INSERT INTO tbl VALUES
('A', 'Active', 1), ('A', 'Inactive', 2)
, ('B', 'Active', 4), ('B', 'Inactive', 5)
, ('C', 'Inactive', 7); -- ('C', 'Active') is missing
Simple form - not fit for missing attributes
crosstab(text) with 1 input parameter:
SELECT *
FROM crosstab(
'SELECT section, status, ct
FROM tbl
ORDER BY 1,2' -- needs to be "ORDER BY 1,2" here
) AS ct ("Section" text, "Active" int, "Inactive" int);
Returns:
Section | Active | Inactive
---------+--------+----------
A | 1 | 2
B | 4 | 5
C | 7 | -- !!
No need for casting and renaming.
Note the incorrect result for C: the value 7 is filled in for the first column. Sometimes, this behavior is desirable, but not for this use case.
The simple form is also limited to exactly three columns in the provided input query: row_name, category, value. There is no room for extra columns like in the 2-parameter alternative below.
Safe form
crosstab(text, text) with 2 input parameters:
SELECT *
FROM crosstab(
'SELECT section, status, ct
FROM tbl
ORDER BY 1,2' -- could also just be "ORDER BY 1" here
, $$VALUES ('Active'::text), ('Inactive')$$
) AS ct ("Section" text, "Active" int, "Inactive" int);
Returns:
Section | Active | Inactive
---------+--------+----------
A | 1 | 2
B | 4 | 5
C | | 7 -- !!
Note the correct result for C.
The second parameter can be any query that returns one row per attribute matching the order of the column definition at the end. Often you will want to query distinct attributes from the underlying table like this:
'SELECT DISTINCT attribute FROM tbl ORDER BY 1'
That's in the manual.
Since you have to spell out all columns in a column definition list anyway (except for pre-defined crosstabN() variants), it is typically more efficient to provide a short list in a VALUES expression like demonstrated:
$$VALUES ('Active'::text), ('Inactive')$$)
Or (not in the manual):
$$SELECT unnest('{Active,Inactive}'::text[])$$ -- short syntax for long lists
I used dollar quoting to make quoting easier.
You can even output columns with different data types with crosstab(text, text) - as long as the text representation of the value column is valid input for the target type. This way you might have attributes of different kind and output text, date, numeric etc. for respective attributes. There is a code example at the end of the chapter crosstab(text, text) in the manual.
db<>fiddle here
Effect of excess input rows
Excess input rows are handled differently - duplicate rows for the same ("row_name", "category") combination - (section, status) in the above example.
The 1-parameter form fills in available value columns from left to right. Excess values are discarded.
Earlier input rows win.
The 2-parameter form assigns each input value to its dedicated column, overwriting any previous assignment.
Later input rows win.
Typically, you don't have duplicates to begin with. But if you do, carefully adjust the sort order to your requirements - and document what's happening.
Or get fast arbitrary results if you don't care. Just be aware of the effect.
Advanced examples
Pivot on Multiple Columns using Tablefunc - also demonstrating mentioned "extra columns"
Dynamic alternative to pivot with CASE and GROUP BY
\crosstabview in psql
Postgres 9.6 added this meta-command to its default interactive terminal psql. You can run the query you would use as first crosstab() parameter and feed it to \crosstabview (immediately or in the next step). Like:
db=> SELECT section, status, ct FROM tbl \crosstabview
Similar result as above, but it's a representation feature on the client side exclusively. Input rows are treated slightly differently, hence ORDER BY is not required. Details for \crosstabview in the manual. There are more code examples at the bottom of that page.
Related answer on dba.SE by Daniel Vérité (the author of the psql feature):
How do I generate a pivoted CROSS JOIN where the resulting table definition is unknown?
SELECT section,
SUM(CASE status WHEN 'Active' THEN count ELSE 0 END) AS active, --here you pivot each status value as a separate column explicitly
SUM(CASE status WHEN 'Inactive' THEN count ELSE 0 END) AS inactive --here you pivot each status value as a separate column explicitly
FROM t
GROUP BY section
You can use the crosstab() function of the additional module tablefunc - which you have to install once per database. Since PostgreSQL 9.1 you can use CREATE EXTENSION for that:
CREATE EXTENSION tablefunc;
In your case, I believe it would look something like this:
CREATE TABLE t (Section CHAR(1), Status VARCHAR(10), Count integer);
INSERT INTO t VALUES ('A', 'Active', 1);
INSERT INTO t VALUES ('A', 'Inactive', 2);
INSERT INTO t VALUES ('B', 'Active', 4);
INSERT INTO t VALUES ('B', 'Inactive', 5);
SELECT row_name AS Section,
category_1::integer AS Active,
category_2::integer AS Inactive
FROM crosstab('select section::text, status, count::text from t',2)
AS ct (row_name text, category_1 text, category_2 text);
DB Fiddle here:
Everything works: https://dbfiddle.uk/iKCW9Uhh
Without CREATE EXTENSION tablefunc; you get this error: https://dbfiddle.uk/j8W1CMvI
ERROR: function crosstab(unknown, integer) does not exist
LINE 4: FROM crosstab('select section::text, status, count::text fro...
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
Solution with JSON aggregation:
CREATE TEMP TABLE t (
section text
, status text
, ct integer -- don't use "count" as column name.
);
INSERT INTO t VALUES
('A', 'Active', 1), ('A', 'Inactive', 2)
, ('B', 'Active', 4), ('B', 'Inactive', 5)
, ('C', 'Inactive', 7);
SELECT section,
(obj ->> 'Active')::int AS active,
(obj ->> 'Inactive')::int AS inactive
FROM (SELECT section, json_object_agg(status,ct) AS obj
FROM t
GROUP BY section
)X
Sorry this isn't complete because I can't test it here, but it may get you off in the right direction. I'm translating from something I use that makes a similar query:
select mt.section, mt1.count as Active, mt2.count as Inactive
from mytable mt
left join (select section, count from mytable where status='Active')mt1
on mt.section = mt1.section
left join (select section, count from mytable where status='Inactive')mt2
on mt.section = mt2.section
group by mt.section,
mt1.count,
mt2.count
order by mt.section asc;
The code I'm working from is:
select m.typeID, m1.highBid, m2.lowAsk, m1.highBid - m2.lowAsk as diff, 100*(m1.highBid - m2.lowAsk)/m2.lowAsk as diffPercent
from mktTrades m
left join (select typeID,MAX(price) as highBid from mktTrades where bid=1 group by typeID)m1
on m.typeID = m1.typeID
left join (select typeID,MIN(price) as lowAsk from mktTrades where bid=0 group by typeID)m2
on m1.typeID = m2.typeID
group by m.typeID,
m1.highBid,
m2.lowAsk
order by diffPercent desc;
which will return a typeID, the highest price bid and the lowest price asked and the difference between the two (a positive difference would mean something could be bought for less than it can be sold).
There's a different dynamic method that I've devised, one that employs a dynamic rec. type (a temp table, built via an anonymous procedure) & JSON. This may be useful for an end-user who can't install the tablefunc/crosstab extension, but can still create temp tables or run anon. proc's.
The example assumes all the xtab columns are the same type (INTEGER), but the # of columns is data-driven & variadic. That said, JSON aggregate functions do allow for mixed data types, so there's potential for innovation via the use of embedded composite (mixed) types.
The real meat of it can be reduced down to one step if you want to statically define the rec. type inside the JSON recordset function (via nested SELECTs that emit a composite type).
dbfiddle.uk
https://dbfiddle.uk/N1EzugHk
Crosstab function is available under the tablefunc extension. You'll have to create this extension one time for the database.
CREATE EXTENSION tablefunc;
You can use the below code to create pivot table using cross tab:
create table test_Crosstab( section text,
status text,
count numeric)
insert into test_Crosstab values ( 'A','Active',1)
,( 'A','Inactive',2)
,( 'B','Active',4)
,( 'B','Inactive',5)
select * from crosstab(
'select section
,status
,count
from test_crosstab'
)as ctab ("Section" text,"Active" numeric,"Inactive" numeric)

Trying to manipulate string such as if '26169;#c785643', then the result should be like 'c785643'

I am trying to manipulate string data in a column such as if the given string is '20591;#e123456;#17507;#c567890;#15518;#e135791' or '26169;#c785643', then the
result should be like 'e123456;c567890;e135791' or 'c785643'. The number of digits in between can be of any length.
Some of the things I have tried so far are:
select replace('20591;#e123456;#17507;#c567890;#15518;#e135791','#','');
This leaves me with '20591;e123456;17507;c567890;15518;e135791', which still includes the digits without 'e' or 'c' prefixed to them. i want to get rid of 20591, 17507 and 15518.
Create function that will keep a pattern of '%[#][ec][0-9][;]%' and will get rid of the rest.
The most important advise is: Do not store any data in a delimited string. This is violating the most basic principle of relational database concepts (1.NF).
The second hint is SO-related: Please always add / tag your questions with the appropriate tool. The tag [tsql] points to SQL-Server, but this might be wrong (which would invalidate both answers). Please tag the full product with its version (e.g. [sql-server-2012]). Especially with string splitting there are very important product related changes from version to version.
Now to your question.
Working with (almost) any version of SQL-Server
My suggestion uses a trick with XML:
(credits to Alan Burstein for the mockup)
DECLARE #table TABLE (someid INT IDENTITY, somestring VARCHAR(50));
INSERT #table VALUES ('20591;#e123456;#17507;#c567890;#15518;#e135791'),('26169;#c785643')
--the query
SELECT t.someid,t.somestring,A.CastedToXml
,STUFF(REPLACE(A.CastedToXml.query('/x[contains(text()[1],"#") and empty(substring(text()[1],2,100) cast as xs:int?)]')
.value('.','nvarchar(max)'),'#',';'),1,1,'') TheNewList
FROM #table t
CROSS APPLY(SELECT CAST('<x>' + REPLACE(t.somestring,';','</x><x>') + '</x>' AS XML)) A(CastedToXml);
The idea in short:
By replacing the ; with XML tags </x><x> we can transform your delimited list to XML. I included the intermediate XML into the result set. Just click it to see how this works.
In the next query I use a XQuery predicate first to find entries, which contain a # and second, which do NOT cast to an integer without the #.
The thrid step is specific to XML again. The XPath . in .value() will return all content as one string.
Finally we have to replace the # with ; and cut away the leading ; using STUFF().
UPDATE The same idea, but a bit shorter:
You can try this as well
SELECT t.someid,t.somestring,A.CastedToXml
,REPLACE(A.CastedToXml.query('data(/x[empty(. cast as xs:int?)])')
.value('.','nvarchar(max)'),' ',';') TheNewList
FROM #table t
CROSS APPLY(SELECT CAST('<x>' + REPLACE(t.somestring,';#','</x><x>') + '</x>' AS XML)) A(CastedToXml);
Here I use ;# to split your string and data() to implicitly concatenate your values (blank-separated).
UPDATE 2 for v2017
If you have v2017+ I'd suggest a combination of a JSON splitter and STRING_AGG():
SELECT t.someid,STRING_AGG(A.[value],';') AS TheNewList
FROM #table t
CROSS APPLY OPENJSON(CONCAT('["',REPLACE(t.somestring,';#','","'),'"]')) A
WHERE TRY_CAST(A.[value] AS INT) IS NULL
GROUP BY t.someid;
You did not include the version of SQL Server you are on. If you are using 2016+ you can use SPLIT_STRING, otherwise a good T-SQL splitter will do.
Against a single variable:
DECLARE #somestring VARCHAR(1000) = '20591;#e123456;#17507;#c567890;#15518;#e135791';
SELECT NewString = STUFF((
SELECT ','+split.item
FROM STRING_SPLIT(#somestring,';') AS s
CROSS APPLY (VALUES(REPLACE(s.[value],'#',''))) AS split(item)
WHERE split.item LIKE '[a-z][0-9]%'
FOR XML PATH('')),1,1,'');
Against a table:
NewString
----------------------
e123456,c567890,e135791
-- Against a table
DECLARE #table TABLE (someid INT IDENTITY, somestring VARCHAR(50));
INSERT #table VALUES ('20591;#e123456;#17507;#c567890;#15518;#e135791'),('26169;#c785643')
SELECT t.*, fn.NewString
FROM #table AS t
CROSS APPLY
(
SELECT NewString = STUFF((
SELECT ','+split.item
FROM STRING_SPLIT(t.somestring,';') AS s
CROSS APPLY (VALUES(REPLACE(s.[value],'#',''))) AS split(item)
WHERE split.item LIKE '[a-z][0-9]%'
FOR XML PATH('')),1,1,'')
) AS fn;
Returns:
someid somestring NewString
----------- -------------------------------------------------- -----------------------------
1 20591;#e123456;#17507;#c567890;#15518;#e135791 e123456,c567890,e135791
2 26169;#c785643 c785643

Make rows to Columns in Postgresql [duplicate]

Does any one know how to create crosstab queries in PostgreSQL?
For example I have the following table:
Section Status Count
A Active 1
A Inactive 2
B Active 4
B Inactive 5
I would like the query to return the following crosstab:
Section Active Inactive
A 1 2
B 4 5
Is this possible?
Install the additional module tablefunc once per database, which provides the function crosstab(). Since Postgres 9.1 you can use CREATE EXTENSION for that:
CREATE EXTENSION IF NOT EXISTS tablefunc;
Improved test case
CREATE TABLE tbl (
section text
, status text
, ct integer -- "count" is a reserved word in standard SQL
);
INSERT INTO tbl VALUES
('A', 'Active', 1), ('A', 'Inactive', 2)
, ('B', 'Active', 4), ('B', 'Inactive', 5)
, ('C', 'Inactive', 7); -- ('C', 'Active') is missing
Simple form - not fit for missing attributes
crosstab(text) with 1 input parameter:
SELECT *
FROM crosstab(
'SELECT section, status, ct
FROM tbl
ORDER BY 1,2' -- needs to be "ORDER BY 1,2" here
) AS ct ("Section" text, "Active" int, "Inactive" int);
Returns:
Section | Active | Inactive
---------+--------+----------
A | 1 | 2
B | 4 | 5
C | 7 | -- !!
No need for casting and renaming.
Note the incorrect result for C: the value 7 is filled in for the first column. Sometimes, this behavior is desirable, but not for this use case.
The simple form is also limited to exactly three columns in the provided input query: row_name, category, value. There is no room for extra columns like in the 2-parameter alternative below.
Safe form
crosstab(text, text) with 2 input parameters:
SELECT *
FROM crosstab(
'SELECT section, status, ct
FROM tbl
ORDER BY 1,2' -- could also just be "ORDER BY 1" here
, $$VALUES ('Active'::text), ('Inactive')$$
) AS ct ("Section" text, "Active" int, "Inactive" int);
Returns:
Section | Active | Inactive
---------+--------+----------
A | 1 | 2
B | 4 | 5
C | | 7 -- !!
Note the correct result for C.
The second parameter can be any query that returns one row per attribute matching the order of the column definition at the end. Often you will want to query distinct attributes from the underlying table like this:
'SELECT DISTINCT attribute FROM tbl ORDER BY 1'
That's in the manual.
Since you have to spell out all columns in a column definition list anyway (except for pre-defined crosstabN() variants), it is typically more efficient to provide a short list in a VALUES expression like demonstrated:
$$VALUES ('Active'::text), ('Inactive')$$)
Or (not in the manual):
$$SELECT unnest('{Active,Inactive}'::text[])$$ -- short syntax for long lists
I used dollar quoting to make quoting easier.
You can even output columns with different data types with crosstab(text, text) - as long as the text representation of the value column is valid input for the target type. This way you might have attributes of different kind and output text, date, numeric etc. for respective attributes. There is a code example at the end of the chapter crosstab(text, text) in the manual.
db<>fiddle here
Effect of excess input rows
Excess input rows are handled differently - duplicate rows for the same ("row_name", "category") combination - (section, status) in the above example.
The 1-parameter form fills in available value columns from left to right. Excess values are discarded.
Earlier input rows win.
The 2-parameter form assigns each input value to its dedicated column, overwriting any previous assignment.
Later input rows win.
Typically, you don't have duplicates to begin with. But if you do, carefully adjust the sort order to your requirements - and document what's happening.
Or get fast arbitrary results if you don't care. Just be aware of the effect.
Advanced examples
Pivot on Multiple Columns using Tablefunc - also demonstrating mentioned "extra columns"
Dynamic alternative to pivot with CASE and GROUP BY
\crosstabview in psql
Postgres 9.6 added this meta-command to its default interactive terminal psql. You can run the query you would use as first crosstab() parameter and feed it to \crosstabview (immediately or in the next step). Like:
db=> SELECT section, status, ct FROM tbl \crosstabview
Similar result as above, but it's a representation feature on the client side exclusively. Input rows are treated slightly differently, hence ORDER BY is not required. Details for \crosstabview in the manual. There are more code examples at the bottom of that page.
Related answer on dba.SE by Daniel Vérité (the author of the psql feature):
How do I generate a pivoted CROSS JOIN where the resulting table definition is unknown?
SELECT section,
SUM(CASE status WHEN 'Active' THEN count ELSE 0 END) AS active, --here you pivot each status value as a separate column explicitly
SUM(CASE status WHEN 'Inactive' THEN count ELSE 0 END) AS inactive --here you pivot each status value as a separate column explicitly
FROM t
GROUP BY section
You can use the crosstab() function of the additional module tablefunc - which you have to install once per database. Since PostgreSQL 9.1 you can use CREATE EXTENSION for that:
CREATE EXTENSION tablefunc;
In your case, I believe it would look something like this:
CREATE TABLE t (Section CHAR(1), Status VARCHAR(10), Count integer);
INSERT INTO t VALUES ('A', 'Active', 1);
INSERT INTO t VALUES ('A', 'Inactive', 2);
INSERT INTO t VALUES ('B', 'Active', 4);
INSERT INTO t VALUES ('B', 'Inactive', 5);
SELECT row_name AS Section,
category_1::integer AS Active,
category_2::integer AS Inactive
FROM crosstab('select section::text, status, count::text from t',2)
AS ct (row_name text, category_1 text, category_2 text);
DB Fiddle here:
Everything works: https://dbfiddle.uk/iKCW9Uhh
Without CREATE EXTENSION tablefunc; you get this error: https://dbfiddle.uk/j8W1CMvI
ERROR: function crosstab(unknown, integer) does not exist
LINE 4: FROM crosstab('select section::text, status, count::text fro...
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
Solution with JSON aggregation:
CREATE TEMP TABLE t (
section text
, status text
, ct integer -- don't use "count" as column name.
);
INSERT INTO t VALUES
('A', 'Active', 1), ('A', 'Inactive', 2)
, ('B', 'Active', 4), ('B', 'Inactive', 5)
, ('C', 'Inactive', 7);
SELECT section,
(obj ->> 'Active')::int AS active,
(obj ->> 'Inactive')::int AS inactive
FROM (SELECT section, json_object_agg(status,ct) AS obj
FROM t
GROUP BY section
)X
Sorry this isn't complete because I can't test it here, but it may get you off in the right direction. I'm translating from something I use that makes a similar query:
select mt.section, mt1.count as Active, mt2.count as Inactive
from mytable mt
left join (select section, count from mytable where status='Active')mt1
on mt.section = mt1.section
left join (select section, count from mytable where status='Inactive')mt2
on mt.section = mt2.section
group by mt.section,
mt1.count,
mt2.count
order by mt.section asc;
The code I'm working from is:
select m.typeID, m1.highBid, m2.lowAsk, m1.highBid - m2.lowAsk as diff, 100*(m1.highBid - m2.lowAsk)/m2.lowAsk as diffPercent
from mktTrades m
left join (select typeID,MAX(price) as highBid from mktTrades where bid=1 group by typeID)m1
on m.typeID = m1.typeID
left join (select typeID,MIN(price) as lowAsk from mktTrades where bid=0 group by typeID)m2
on m1.typeID = m2.typeID
group by m.typeID,
m1.highBid,
m2.lowAsk
order by diffPercent desc;
which will return a typeID, the highest price bid and the lowest price asked and the difference between the two (a positive difference would mean something could be bought for less than it can be sold).
There's a different dynamic method that I've devised, one that employs a dynamic rec. type (a temp table, built via an anonymous procedure) & JSON. This may be useful for an end-user who can't install the tablefunc/crosstab extension, but can still create temp tables or run anon. proc's.
The example assumes all the xtab columns are the same type (INTEGER), but the # of columns is data-driven & variadic. That said, JSON aggregate functions do allow for mixed data types, so there's potential for innovation via the use of embedded composite (mixed) types.
The real meat of it can be reduced down to one step if you want to statically define the rec. type inside the JSON recordset function (via nested SELECTs that emit a composite type).
dbfiddle.uk
https://dbfiddle.uk/N1EzugHk
Crosstab function is available under the tablefunc extension. You'll have to create this extension one time for the database.
CREATE EXTENSION tablefunc;
You can use the below code to create pivot table using cross tab:
create table test_Crosstab( section text,
status text,
count numeric)
insert into test_Crosstab values ( 'A','Active',1)
,( 'A','Inactive',2)
,( 'B','Active',4)
,( 'B','Inactive',5)
select * from crosstab(
'select section
,status
,count
from test_crosstab'
)as ctab ("Section" text,"Active" numeric,"Inactive" numeric)

TSQL - Parsing substring out of larger string

I have a bunch of rows with values that look like below. It's json extract that I unfortunately have to parse out and load. Anyway, my json parsing tool for some reason doesn't want to parse this full column out so i need to do it in TSQL. I only need the unique_id field:
[{"unique_id":"12345","system_type":"Test System."}]
I tried the below SQL but it's only returning the first 5 characters of the whole column. I know what the issue is which is I need to know how to tell the substring to continue until the 4th set of quotes which comes after the value. I'm not sure how to code the substring like that.
select substring([jsonfield],CHARINDEX('[{"unique_id":"',[jsonfield]),
CHARINDEX('"',[jsonfield]) - CHARINDEX('[{"unique_id":"',[jsonfield]) +
LEN('"')) from etl.my_test_table
Can anyone help me with this?
Thank you, I appreciate it!
Since you tagged 2016, why not use OPENJSON()
Here's an example:
DECLARE #TestData TABLE
(
[SampleData] NVARCHAR(MAX)
);
INSERT INTO #TestData (
[SampleData]
)
VALUES ( N'[{"unique_id":"12345","system_type":"Test System."}]' )
,( N'[{"unique_id":"1234567","system_type":"Test System."},{"unique_id":"1234567_2","system_type":"Test System."}]' )
SELECT b.[unique_id]
FROM #TestData [a]
CROSS APPLY
OPENJSON([a].[SampleData], '$')
WITH (
[unique_id] NVARCHAR(100) '$.unique_id'
) AS [b];
Giving you:
unique_id
---------------
12345
1234567
1234567_2
You can get all the fields as well, just add them to the WITH clause:
SELECT [b].[unique_id]
, [b].[system_type]
FROM #TestData [a]
CROSS APPLY
OPENJSON([a].[SampleData], '$')
WITH (
[unique_id] NVARCHAR(100) '$.unique_id'
, [system_type] NVARCHAR(100) '$.system_type'
) AS [b];
Take it step by step
First get everything to the left of system_type
SELECT LEFT(jsonfield, CHARINDEX('","system_type":"',jsonfield) as s
FROM -- etc
Then take everything to the right of "unique_id":"
SELECT RIGHT(S, LEN(S) - (CHARINDEX('"unique_id":"',S) + 12)) as Result
FROM (
SELECT LEFT(jsonfield, CHARINDEX('","system_type":"',jsonfield) as s
FROM -- etc
) X
Note, I did not test this so it could be off by one or have a syntax error, but you get the idea.
If your larger string ist just a simple JSON as posted, the solution is very easy:
SELECT
JSON_VALUE(N'[{"unique_id":"12345","system_type":"Test System."}]','$[0].unique_id');
JSON_VALUE() needs SQL-Server 2016 and will extract one single value from a specified path.

TSQL split comma delimited string

I am trying to create a stored procedure that will split 3 text boxes on a webpage that have user input that all have comma delimited strings in it. We have a field called 'combined_name' in our table that we have to search for first and last name and any known errors or nicknames etc. such as #p1: 'grei,grie' #p2: 'joh,jon,j..' p3: is empty.
The reason for the third box is after I get the basics set up we will have does not contain, starts with, ends with and IS to narrow our results further.
So I am looking to get all records that CONTAINS any combination of those. I originally wrote this in LINQ but it didn't work as you cannot query a list and a dataset. The dataset is too large (1.3 million records) to be put into a list so I have to use a stored procedure which is likely better anyway.
Will I have to use 2 SP, one to split each field and one for the select query or can this be done with one? What function do I use for contains in tsql? I tried using IN win a query but cannot figure out how it works with multiple parameters.
Please note that this will be an internal site that has limited access so worrying about sql injection is not a priority.
I did attempt dynamic SQL but am not getting the correct results back:
CREATE PROCEDURE uspJudgments #fullName nvarchar(100) AS
EXEC('SELECT *
FROM new_judgment_system.dbo.defendants_ALL
WHERE combined_name IN (' + #fullName + ')')
GO
EXEC uspJudgments #fullName = '''grein'', ''grien'''
Even if this did retrieve the correct results how would this be done with 3 parameters?
You may try use this to split string and obtain a tables of strings. Then to have all the combinations you may use full join of these two tables. And then do your select.
Here is the Table valued function I set up:
ALTER FUNCTION [dbo].[Split] (#sep char(1), #s varchar(8000))
RETURNS table
AS
RETURN (
WITH splitter_cte AS (
SELECT CHARINDEX(#sep, #s) as pos, 0 as lastPos
UNION ALL
SELECT CHARINDEX(#sep, #s, pos + 1), pos
FROM splitter_cte
WHERE pos > 0
)
SELECT SUBSTRING(#s, lastPos + 1,
case when pos = 0 then 80000
else pos - lastPos -1 end) as OutputValues
FROM splitter_cte
)
)