CASE ReGex with substring - sql

I'm writing a SQL query where I am taking the substring of 2 names (First name/last name) to create an initials column, the data is unstructured to a certain extent (Can't show for GDPR reasons) but where there is a company name it is just in the surname column.
I'm trying to use Regex to say when the already present initials column is 1 letter (I.e not an initial) and if it is not an initial run a command that I wrote which successfully works.
CAST(CASE
WHEN [DATA_TABLE].[INITIALS] = '\d' THEN (CONCAT(substring([DATA_TABLE].[FIRSTNAMES],1,1),substring([DATA_TABLE].[SURNAME],1,1)) AS char) AS INITIALS
ELSE [DATA_TABLE].[INITIALS]
end as char) as INITIALS,
An example of the data format:
First name last name initials
John smith JS
Electrical company E
Sam Craig SC
I want the names that are just in the surname (Company names) to just remain as they are with no change (I.e The \d regex). Ones which don't will become the substring of their first name as (1,1) and a substring of their last name to also be (1,1).

Related

SQL WHERE column values into capital letters

Let's say I have the following entries in my database:
Id
Name
12
John Doe
13
Mary anne
13
little joe
14
John doe
In my program I have a string variable that is always capitalized, for example:
myCapString = "JOHN DOE"
Is there a way to retrieve the rows in the table by using a WHERE on the name column with the values capitalized and then matching myCapString?
In this case the query would return two entries, one with id=12, and one with id=14
A solution is NOT to change the actual values in the table.
A general solution in Postgres would be to capitalize the Name column and then do a comparison against an all-caps string literal, e.g.
SELECT *
FROM yourTable
WHERE UPPER(Name) = 'JOHN DOE';
If you need to implement this is Knex, you will need to figure out how to uppercase a column. This might require using a raw query.

Using LIKE clause when formats are different

I was given a patient list with names and I am trying to match with a list already in our database and am having troubles given the format of the name field in the patient list. This list is taken from a web form so people can input names however they want so it does not match up well.
WEBFORM_NAME
PATIENT_NAME
JOHN SMITH
SMITH,JOHN L
SHANNON BROWN
BROWN,SHANNON MARIE
Is there a way to use a LIKE clause in an instance like this? All I really need is the LIKE clause to find the first name because I have joined on phone number and email address already. My issue is when households have the same phone number and email address (spouses for example) I just want to return the right person in the household.
Not sure if all you need is to get first name, here is the WIldCard expression to get first name
SELECT LEFT(WEBFORM_NAME,CHARINDEX(' ',WEBFORM_NAME)-1) AS FirstName1,
SUBSTRING(PATIENT_NAME,CHARINDEX(',',PATIENT_NAME)+1,(CHARINDEX(' ',PATIENT_NAME)-CHARINDEX(',',PATIENT_NAME))) AS FirstName2
FROM yourTable
The assumption here seems to be that the webform (where user would manually) type in the name would be of the format <First Name> [<optional middle Name(s)>] <Last Name>, where as the data stored in the table are of the form <Last Name>,<First Name> [<optional middle Name(s)>]. Its not an exact science, but since other criteria (like email, phone etc) have been matched best case
select *
from webform w, patient p
where
-- extract just the last name and match that
regexp_like(p.name,
'^' ||
regexp_extract(w.name,
'([^[:space:],][[:space:],])*([^[:space:],]+)', 1, 2))
and -- extract the first name and match it
regexp_like(p.name,
',[[:space:]]*' ||
regexp_extract(w.name, '(^[^[:space:],]+)'))
Since webform is free form user input, its hard to handle abbreviated middle name(s) and other variations so using the above will do first name and last name based matching which in addition to the matching you are already doing should help.

SQL query to get the first letter of each word and seperate it by a dot and a space

I have never really used SQL much but recent changes due to working from home is forcing me to gain some knowledge in it. I have been doing fine so far but I am now running into a problem that I can't seem to find a solution for.
I have an excel sheet that pulls customer information trough a SQL query which runs by VBA code.
What I first needed to do is to get a full name from a customer and input this into the sheet. This works fine. I am using the following query for this:
Select concat(concat(Customer_First_Names,' '), Customer_Last_Name) FROM CustomerInformationTable where Customer_Number = &&1
This gives me the full name of a customer and spaces in between the first and last name and in between the names (the full first names are already spaced in between in the table).
Now, I got another request to not retrieve the first full first names and last name of a customer, but their initials and the last name.
For example:
Barack Hussein Obama
Would become
B. H. Obama
I need to do 2 things for this:
I need to change my query to retrieve only the initials for each first name. Like I said, all full first names (even if a customer has more then one first name) is located in the column Customer_First_Names.
I need to add a dot and a space after each initial.
How would I go on about this?
I have been thinking about using SUBSTRING but I am struggling on how to do this if there is more then one first name.
So this is not going to work:
Select concat(substr(Customer_First_Names, 1, 1), '. ') from CustomerInformationTable where Customer_Number = &&1
My apologies if this has already been ask on the board so far, I looked but I did not find a suitable solution.
Assuming you don't want to see 2 dots after someone who has just one first name (like J.. Smith), then here's a solution that works in postgres. Not sure what your db is, so you may need to adjust as needed.
The 'with' query is splitting apart the first names, limiting to two.
The 'case' statement then checks if the person has a second first name. If not, then only the first initial is provided and followed by a dot. Otherwise, both first initials are followed by a dot. Final results, all initials and names are separated by a space (like T. R. Smith).
So, a table looking like this:
cid first last
1 JAKE SMITH
2 TERREL HOWARD WILLIAMS
3 PHOEBE M KATES
Will produce the following results with the query below.
cid cust_name
1 J. SMITH
2 T. H. WILLIAMS
3 P. M. KATES
with first_names as
(select distinct customer_number ,
split_part(customer_first_name, ' ', 1) as first1,
split_part(customer_first_name, ' ', 2) as first2
from CustomerInformationTable
)
select distinct customer_number,
case
when fn.first2 = '' then substring(fn.first1, 1, 1) || '.'
else substring(fn.first1, 1, 1) || '. ' || substring(fn.first2, 1, 1) || '.'
end
|| ' ' || a.customer_last_name as cust_name
from CustomerInformationTable a
join first_names fn on fn.customer_number = a.customer_number

Name Correction

Name Correction
As the wedding season is on, John has been given the work of printing guest names on wedding cards. John has written code to print only those names that start with upper-case alphabets and reject those that start with lower-case alphabets or special characters.
Your job is to do the following:
1.Correct the rejected names (names which start with lower case or with a special character). You have to change the first alphabet of the rejected name to Upper case and in the case of special character there will be no change.
2.Output the newly corrected names in ascending order.
Table format
Table: person
Field Type
name varchar(20)
Sample
Sample person table
name
mohit
Kunal
manoj
Raj
tanya
#man
Sample output table
name
#man
Manoj
Mohit
Tanya
Solution Attempted: IN SQL SERVER 2014
select name
from person as per
where (left(per.name,1) like '%[^A-Z]%' or left(per.name,1) like '% %')
union
select Upper(left(per.name,1))+right(per.name,len(per.name)-1)
from person as per
where left(per.name,1)<>left(Upper(per.name),1)
collate Latin1_General_CS_AI
order by per.name
Sample Test Cases Passes,
Still getting wrong answer in some competitor exam.
Please suggest what test case i have not handled.
Since you are only interested in correcting lower case and reporting special characters in the first character position I would use ascii comparision rather than regex.
select name, ascii(left(name,1)),
case
when ascii(left(name,1)) between 97 and 122 then
concat(char(ascii(left(name,1)) - 32),substring(name,2,len(name) -1))
else name
end name
from t
where ascii(left(name,1)) <= 64 or
ascii(left(name,1)) >= 91

How do you query only part of the data in the row of a column - Microsoft SQL Server

I have a column called NAME, I have 2000 rows in that column that are filled with people's full names, e.g. ANN SMITH. How do I do a query that will list all the people whose first name is ANN? There are about 20 different names whose first name is ANN but the surname is different.
I tried
and (NAME = 'ANN')
but it returned zero results.
I have to enter the FULL name and (NAME = 'ANN SMITH') ANN SMITH to even get a result .
I just want to list all the people with there first name as ANN
Try in your where clause:
Where Name like 'ANN %'
Should work mate.
ANN% will find all results where ANN is first then anything after.
%ANN% will find the 3 letters ANN in any part of that rows field.
Hope it helps
Also usually Name is separated into First names and second name columns.
this will save Having to use wild cards in your SQL and provide A bit more normalized data.
SELECT NAME
FROM NAMES
WHERE NAME LIKE 'ANN %'
This should wildcard select anything that begins with 'ANN' followed by a space.