Question

I am trying to add a query in my current SQL INSERT INTO statement. Below is my table and current sql statement.

I have 3 tables:

Table1: UserID, Username.

Table2: UserID, Status.

Table3: UserID, Username, Issue

Currently I only have 3 SELECT statement which fulfills the above 3 checks and INSERT the result into Table3:

 1.
    Insert in to Table3(userid,issue)
        SELECT t1.userid,'check no.1'
        FROM table1 t1
        FULL OUTER JOIN table2 t2 ON t1.userid = t2.userid
        where t1.userid not null and t2.userid is null
2.
    Insert in to Table3(userid,issue)
        SELECT t1.userid,'check no.2'
        FROM table1 t1
        inner JOIN table2 t2 ON t1.userid = t2.userid
        where t2.status = 'DELETE'

3.
    Insert in to Table3(userid,issue)
        SELECT t2.userid,'check no.3'
        FROM table2 t2
        right outer JOIN table2 t2 ON t1.userid = t2.userid
        where t2.status <> 'DELETE' and t1.userid is null

Now I wish to add in another additional check which is to check for duplicated userid in BOTH T1 AND T2:

1. Check for same userid with same caps (e.g. E01 and E01 should not exist)
2. Check for same userid but different caps (e.g. E01 and e01 should not exist)

How can I code the 4th sql query which specially checks for duplicated userids?

Thank you for the help.

Answer 1

Edited:

INSERT INTO Table3(userid, Username, issue)
SELECT 
    userid, Username, 'Duplicate UserID' 
FROM 
    (
        SELECT 
                userid, 
                Username, 
                RANK() OVER (PARTITION BY userid ORDER BY userid) AS [RANK] 
        FROM 
            Table1 --table2
    ) X
WHERE 
    [RANK]=2


INSERT INTO Table3(userid, Username, issue)
SELECT 
    userid, [status], 'Duplicate UserID' 
FROM 
    (
        SELECT 
                userid, 
                [status], 
                RANK() OVER (PARTITION BY userid ORDER BY userid) AS [RANK] 
        FROM 
            Table2
    ) X
WHERE 
    [RANK]=2

You can use the COLLATE as shown in the OLD section to do a case sensitive check, if you need.

I used RANK=2 to insert only one entry for duplicate userID

OLD:
You can use the COLLATE to do a case sensitive check

INSERT INTO Table3(UserId, Username, Issue)
    SELECT 
    COALESCE(t1.UserId, t2.UserId), 
    t1.UserName,
    CASE        
        WHEN (t2.userid IS NULL AND t1.userid IS NOT NULL)
            THEN 'User exists in t1 but not in t2'
        WHEN (t2.status = 'DELETE' AND t1.userid IS NOT NULL)
            THEN 'User Exists in t1, but status in t2 is DELETE'
        WHEN (t2.userid IS NOT NULL AND t2.status != 'DELETE' AND t1.userid IS NULL)
            THEN 'Non-Deleted user in t2 does not exist in t1'
        WHEN t1.userid COLLATE SQL_Latin1_General_CP1_CS_AS = t2.userid COLLATE SQL_Latin1_General_CP1_CS_AS
            THEN 'Duplicate userid with same caps'
        WHEN t1.userid = t2.userid
            THEN 'Duplicate userid but different caps'
     END
FROM table1 t1
FULL OUTER JOIN table2 t2 ON t1.userid = t2.userid
WHERE 
    (t1.userid IS NOT NULL AND t2.userid IS NOT NULL AND t2.status != 'DELETE' AND t1.userid = t2.userid) OR    
    (t2.userid IS NULL AND t1.userid IS NOT NULL) OR 
    (t2.status = 'DELETE' AND t1.userid IS NOT NULL) OR 
    (t2.userid IS NOT NULL AND t2.status != 'DELETE' AND t1.userid IS NULL)