I'm trying to fill a table with rows that should be there: If a city in #Maps does not exist in #Results, then I will fill it using NOT EXISTS. The issue is that the filterisused = 1 not only is ignored, it seems to void the NOT EXISTS.
With IsUsed = 1, everything in #Maps will be inserted to #Results regardless if it exists or not.
If I remove IsUsed = 1, both rows from NY are inserted (correct behavior but not what I'm looking for).
Here's the code:
declare #Maps table
(
Name varchar(20),
IsUsed bit,
Code varchar(20)
)
insert into #Maps
select 'NY', 1, 'NY1'
union select 'NY', 0, 'NY2'
union select 'FL', 0, 'FL1'
union select 'TX', 0, 'TX1'
declare #Results table
(
Name varchar(20),
Value int,
Code varchar(20)
)
insert into #results
select 'FL', 12, 'FL1'
union
select 'TX', 54,'TX1'
union
select 'CA', 54,'CA1'
union
select 'NJ', 54,'NJ1'
insert into #results
select Name, 999, code from #Maps m
-- This adds everything even if it exists
where not exists (select name from #Results p where p.name = m.name and IsUsed = 1)
-- This adds both 'NY'. Partially correct but adds column IsUsed = 0
-- where not exists (select name from #Results p where p.name = m.name)
select * from #results
How can I add the one row that's not included in #results and has IsUsed equal to 1? In this case it would be {'NY', 1, 'NY1}`.
I understand that there are many ways of accomplishing this, but I'm interested in knowing how the where clause in not exists work.
You have to remove the IsUsed=1 from the NOT EXISTS and add it to the WHERE:
insert into #results
select Name, 999, code
from #Maps m
where m.IsUsed = 1
and not exists (select name from #Results p where p.name = m.name)
I think you confuse how an insert select works. The select is run independently. The insert is not committed until the end of the statement. See all the inserted cnt is 4.
declare #maps table(name varchar(10), isUsed bit, code varchar(10));
insert into #Maps values
('NY', 1, 'NY1')
, ('NY', 0, 'NY2')
, ('FL', 0, 'FL1')
, ('TX', 0, 'TX1')
declare #Results table (Name varchar(20), Value int, Code varchar(20), cnt int)
insert into #results values
('FL', 12, 'FL1', null)
, ('TX', 54, 'TX1', null)
, ('CA', 54, 'CA1', null)
, ('NJ', 54, 'NJ1', null)
select * from #results;
insert into #Results
select m.Name, 999, m.code
, (select count(*) from #results) as cnt
from #Maps m
where not exists (select name
from #Results p
where p.name = m.name
and m.IsUsed = 1)
select * from #results;
On the first NY where p.name = m.name is false so not exits is true
On the second NY where p.name = m.name is false so not exits is true
The first NY as not been committed
On the FL and TL the where p.name = m.name is true but m.IsUsed = 1 is false so not exits is true
Related
I have a scenario where almost all of the tables have issues with the PK value as follows. This results is a database error or the violation of the PK insert.
When using the DBCC CheckIdent it displays an inconsistency between the next value and the current one.
Can anyone have a reason for the mismatch happening on several tables?
Since this database is then replicate, I'm afraid this error will propagate across the environment.
I adapted this script to fix it, but really trying to figure out the root of the problem.
/** Version 3.0 **/
if object_id('tempdb..#temp') is not null
drop table #temp
;
with cte as (
SELECT
distinct
A.TABLE_CATALOG AS CATALOG,
A.TABLE_SCHEMA AS "SCHEMA",
A.TABLE_NAME AS "TABLE",
B.COLUMN_NAME AS "COLUMN",
IDENT_SEED (A.TABLE_NAME) AS Seed,
IDENT_INCR (A.TABLE_NAME) AS Increment,
IDENT_CURRENT (A.TABLE_NAME) AS Curr_Value
, DBPS.row_count AS NumberOfRows
FROM INFORMATION_SCHEMA.TABLES A
inner join INFORMATION_SCHEMA.COLUMNS B on b.TABLE_NAME = a.TABLE_NAME and b.TABLE_SCHEMA = a.TABLE_SCHEMA
inner join sys.identity_columns IC on OBJECT_NAME (IC.object_id) = a.TABLE_NAME
inner join sys.dm_db_partition_stats DBPS ON DBPS.object_id =IC.object_id
inner join sys.indexes as IDX ON DBPS.index_id =IDX.index_id
WHERE A.TABLE_CATALOG = B.TABLE_CATALOG AND
A.TABLE_SCHEMA = B.TABLE_SCHEMA AND
A.TABLE_NAME = B.TABLE_NAME AND
COLUMNPROPERTY (OBJECT_ID (B.TABLE_NAME), B.COLUMN_NAME, 'IsIdentity') = 1 AND
OBJECTPROPERTY (OBJECT_ID (A.TABLE_NAME), 'TableHasIdentity') = 1 AND
A.TABLE_TYPE = 'BASE TABLE'
)
select 'DBCC CHECKIDENT ('''+A.[SCHEMA]+'.'+a.[TABLE]+''', reseed)' command
, ROW_NUMBER() OVER(ORDER BY a.[SCHEMA], a.[TABLE] asc) AS ID
, A.Curr_Value
, a.[TABLE]
into #temp
from cte A
ORDER BY A.[SCHEMA], A.[TABLE]
declare #i int = 1, #count int = (select max(ID) from #temp)
declare #text varchar(max) = ''
select #COUNT= count(1) FROM #temp
WHILE #I <= #COUNT
BEGIN
SET #text = (SELECT command from #temp where ID=#I)
EXEC (#text + ';')
print #text
select Curr_Value OldValue, ident_current([TABLE]) FixValue, [TABLE] from #temp where ID=#I
SET #I = #I + 1
SET #text='';
END
go
maybe someone or something with enough permissions made a mistake by reseeding?
As simple as this:
create table testid (
id int not null identity (1,1) primary key,
data varchar (3)
)
insert into testid (data) values ('abc'),('cde')
DBCC CHECKIDENT ('testid', RESEED, 1)
insert into testid (data) values ('bad')
I need to get a tree of related nodes given a certain node, but not necessary top node. I've got a solution using two CTEs, since I am struggling to squeeze it all into one CTE :). Might somebody have a sleek solution to avoid using two CTEs? Here is some code that I was playing with:
DECLARE #temp AS TABLE (ID INT, ParentID INT)
INSERT INTO #temp
SELECT 1 ID, NULL AS ParentID
UNION ALL
SELECT 2, 1
UNION ALL
SELECT 3, 2
UNION ALL
SELECT 4, 3
UNION ALL
SELECT 5, 4
UNION ALL
SELECT 6, NULL
UNION ALL
SELECT 7, 6
UNION ALL
SELECT 8, 7
DECLARE #startNode INT = 4
;WITH TheTree (ID,ParentID)
AS (
SELECT ID, ParentID
FROM #temp
WHERE ID = #startNode
UNION ALL
SELECT t.id, t.ParentID
FROM #temp t
JOIN TheTree tr ON t.ParentID = tr.ID
)
SELECT * FROM TheTree
;WITH Up(ID,ParentID)
AS (
SELECT t.id, t.ParentID
FROM #temp t
WHERE t.ID = #startNode
UNION ALL
SELECT t.id, t.ParentID
FROM #temp t
JOIN Up c ON t.id = c.ParentID
)
--SELECT * FROM Up
,TheTree (ID,ParentID)
AS (
SELECT ID, ParentID
FROM Up
WHERE ParentID is null
UNION ALL
SELECT t.id, t.ParentID
FROM #temp t
JOIN TheTree tr ON t.ParentID = tr.ID
)
SELECT * FROM TheTree
thanks
Meh. This avoids using two CTEs, but the result is a brute force kludge that hardly qualifies as "sleek" as it won’t be efficient if your table is at all sizeable. It will:
Recursively build all possible hierarchies
As you build them, flag the target NodeId as you find it
Return only the targeted tree
I threw in column “TreeNumber” on the off-chance the TargetId appears in multiple hierarchies, or if you’d ever have multiple values to check in one pass. “Depth” was added to make the output a bit more legible.
A more complex solution like #John’s might do, and more and subtler tricks could be done with more detailed table sturctures.
DECLARE #startNode INT = 4
;WITH cteAllTrees (TreeNumber, Depth, ID, ParentID, ContainsTarget)
AS (
SELECT
row_number() over (order by ID) TreeNumber
,1
,ID
,ParentID
,case
when ID = #startNode then 1
else 0
end ContainsTarget
FROM #temp
WHERE ParentId is null
UNION ALL
SELECT
tr.TreeNumber
,tr.Depth + 1
,t.id
,t.ParentID
,case
when tr.ContainsTarget = 1 then 1
when t.ID = #startNode then 1
else 0
end ContainsTarget
FROM #temp t
INNER JOIN cteAllTrees tr
ON t.ParentID = tr.ID
)
SELECT
TreeNumber
,Depth
,ID
,ParentId
from cteAllTrees
where TreeNumber in (select TreeNumber from cteAllTrees where ContainsTarget = 1)
order by
TreeNumber
,Depth
,ID
Here is a technique where you can select the entire hierarchy, a specific node with all its children, and even a filtered list and how they roll.
Note: See the comments next to the DECLAREs
Declare #YourTable table (id int,pt int,name varchar(50))
Insert into #YourTable values
(1,null,'1'),(2,1,'2'),(3,1,'3'),(4,2,'4'),(5,2,'5'),(6,3,'6'),(7,null,'7'),(8,7,'8')
Declare #Top int = null --<< Sets top of Hier Try 2
Declare #Nest varchar(25) = '|-----' --<< Optional: Added for readability
Declare #Filter varchar(25) = '' --<< Empty for All or try 4,6
;with cteP as (
Select Seq = cast(1000+Row_Number() over (Order by name) as varchar(500))
,ID
,pt
,Lvl=1
,name
From #YourTable
Where IsNull(#Top,-1) = case when #Top is null then isnull(pt,-1) else ID end
Union All
Select Seq = cast(concat(p.Seq,'.',1000+Row_Number() over (Order by r.name)) as varchar(500))
,r.ID
,r.pt
,p.Lvl+1
,r.name
From #YourTable r
Join cteP p on r.pt = p.ID)
,cteR1 as (Select *,R1=Row_Number() over (Order By Seq) From cteP)
,cteR2 as (Select A.Seq,A.ID,R2=Max(B.R1) From cteR1 A Join cteR1 B on (B.Seq like A.Seq+'%') Group By A.Seq,A.ID )
Select Distinct
A.R1
,B.R2
,A.ID
,A.pt
,A.Lvl
,name = Replicate(#Nest,A.Lvl-1) + A.name
From cteR1 A
Join cteR2 B on A.ID=B.ID
Join (Select R1 From cteR1 where IIF(#Filter='',1,0)+CharIndex(concat(',',ID,','),concat(',',#Filter+','))>0) F on F.R1 between A.R1 and B.R2
Order By A.R1
I would like to know how to write a postgres subquery so that the following table example will output what I need.
id parent_id postdate
1 -1 2015-03-10
2 1 2015-03-11 (child level 1)
3 1 2015-03-12 (child level 1)
4 3 2015-03-13 (child level 2)
5 -1 2015-03-14
6 -1 2015-03-15
7 6 2015-03-16 (child level 1)
If I want to sort all the root ids by child level 1 with a count of children(s) from the parent, the output would be something like this
id count date
6 2 2015-03-15
1 4 2015-03-10
5 1 2015-03-14
The output is sorted by postdate based on the root's child. The 'date' being outputted is the date of the root's postdate. Even though id#5 has a more recent postdate, the rootid#6's child (id#7) has the most recent postdate because it is being sorted by child's postdate. id#5 doesnt have any children so it just gets placed at the end, sorted by date. The 'count' is the number children(child level 1), grandchildren(child level 2) and itself (root). For instance, id #2,#3,#4 all belong to id#1 so for id#1, the count would be 4.
My current subquery thus far:
SELECT p1.id,count(p1.id),p1.postdate
FROM mytable p1
LEFT JOIN mytable c1 ON c1.parent_id = p1.id AND p1.parent_id = -1
LEFT JOIN mytable c2 ON c2.parent_id = c1.id AND p1.parent_id = -1
GROUP BY p1.id,c1.postdate,p1.postdate
ORDER by c1.postdate DESC,p1.postdate DESC
create table mytable ( id serial primary key, parent_id int references mytable, postdate date );
create index mytable_parent_id_idx on mytable (parent_id);
insert into mytable (id, parent_id, postdate) values (1, null, '2015-03-10');
insert into mytable (id, parent_id, postdate) values (2, 1, '2015-03-11');
insert into mytable (id, parent_id, postdate) values (3, 1, '2015-03-12');
insert into mytable (id, parent_id, postdate) values (4, 3, '2015-03-13');
insert into mytable (id, parent_id, postdate) values (5, null, '2015-03-14');
insert into mytable (id, parent_id, postdate) values (6, null, '2015-03-15');
insert into mytable (id, parent_id, postdate) values (7, 6, '2015-03-16');
with recursive recu as (
select id as parent, id as root, null::date as child_postdate
from mytable
where parent_id is null
union all
select r.parent, mytable.id, mytable.postdate
from recu r
join mytable
on parent_id = r.root
)
select m.id, c.cnt, m.postdate, c.max_child_date
from mytable m
join ( select parent, count(*) as cnt, max(child_postdate) as max_child_date
from recu
group by parent
) c on c.parent = m.id
order by c.max_child_date desc nulls last, m.postdate desc;
You'll need a recursive query to count the elements in the subtrees:
WITH RECURSIVE opa AS (
SELECT id AS par
, id AS moi
FROM the_tree
WHERE parent_id IS NULL
UNION ALL
SELECT o.par AS par
, t.id AS moi
FROM opa o
JOIN the_tree t ON t.parent_id = o.moi
)
SELECT t.id
, c.cnt
, t.postdate
FROM the_tree t
JOIN ( SELECT par, COUNT(*) AS cnt
FROM opa o
GROUP BY par
) c ON c.par = t.id
ORDER BY t.id
;
UPDATE (it appears the OP also wants the maxdate per tree)
-- The same, but also select the postdate
-- --------------------------------------
WITH RECURSIVE opa AS (
SELECT id AS par
, id AS moi
, postdate AS postdate
FROM the_tree
WHERE parent_id IS NULL
UNION ALL
SELECT o.par AS par
, t.id AS moi
-- , GREATEST(o.postdate,t.postdate) AS postdate
, t.postdate AS postdate
FROM opa o
JOIN the_tree t ON t.parent_id = o.moi
)
SELECT t.id
, c.cnt
, t.postdate
, c.maxdate
FROM the_tree t
JOIN ( SELECT par, COUNT(*) AS cnt
, MAX(o.postdate) AS maxdate -- and obtain the max()
FROM opa o
GROUP BY par
) c ON c.par = t.id
ORDER BY c.maxdate, t.id
;
After looking at everyone's code, I created the subquery I needed. I can use PHP to vary the 'case when' code depending on the user's sort selection. For instance, the code below will sort the root nodes based on child level 1's postdate.
with recursive cte as (
select id as parent, id as root, null::timestamp as child_postdate,0 as depth
from mytable
where parent_id = -1
union all
select r.parent, mytable.id, mytable.postdate,depth+1
from cte r
join mytable
on parent_id = r.root
)
select m.id, c.cnt, m.postdate
from ssf.dtb_021 m
join ( select parent, count(*) as cnt, max(child_postdate) as max_child_date,depth
from cte
group by parent,depth
) c on c.parent = m.id
order by
case
when depth=2 then 1
when depth=1 then 2
else 0
end DESC,
c.max_child_date desc nulls last, m.postdate desc;
select
p.id,
(1+c.n) as parent_post_plus_number_of_subposts,
p.postdate
from
table as p
inner join
(
select
parent_id, count(*) as n, max(postdate) as _postdate
from table
group by parent_id
) as c
on p.id = c.parent_id
where p.parent_id = -1
order by c._postdate desc
Table name: Table1
id name
1 1-aaa-14 milan road
2 23-abcde-lsd road
3 2-mnbvcx-welcoome street
I want the result like this:
Id name name1 name2
1 1 aaa 14 milan road
2 23 abcde lsd road
3 2 mnbvcx welcoome street
This function ought to give you what you need.
--Drop Function Dbo.Part
Create Function Dbo.Part
(#Value Varchar(8000)
,#Part Int
,#Sep Char(1)='-'
)Returns Varchar(8000)
As Begin
Declare #Start Int
Declare #Finish Int
Set #Start=1
Set #Finish=CharIndex(#Sep,#Value,#Start)
While (#Part>1 And #Finish>0)Begin
Set #Start=#Finish+1
Set #Finish=CharIndex(#Sep,#Value,#Start)
Set #Part=#Part-1
End
If #Part>1 Set #Start=Len(#Value)+1 -- Not found
If #Finish=0 Set #Finish=Len(#Value)+1 -- Last token on line
Return SubString(#Value,#Start,#Finish-#Start)
End
Usage:
Select ID
,Dbo.Part(Name,1,Default)As Name
,Dbo.Part(Name,2,Default)As Name1
,Dbo.Part(Name,3,Default)As Name2
From Dbo.Table1
It's rather compute-intensive, so if Table1 is very long you ought to write the results to another table, which you could refresh from time to time (perhaps once a day, at night).
Better yet, you could create a trigger, which automatically updates Table2 whenever a change is made to Table1. Assuming that column ID is primary key:
Create Table Dbo.Table2(
ID Int Constraint PK_Table2 Primary Key,
Name Varchar(8000),
Name1 Varchar(8000),
Name2 Varchar(8000))
Create Trigger Trigger_Table1 on Dbo.Table1 After Insert,Update,Delete
As Begin
If (Select Count(*)From Deleted)>0
Delete From Dbo.Table2 Where ID=(Select ID From Deleted)
If (Select Count(*)From Inserted)>0
Insert Dbo.Table2(ID, Name, Name1, Name2)
Select ID
,Dbo.Part(Name,1,Default)
,Dbo.Part(Name,2,Default)
,Dbo.Part(Name,3,Default)
From Inserted
End
Now, do your data manipulation (Insert, Update, Delete) on Table1, but do your Select statements on Table2 instead.
The below solution uses a recursive CTE for splitting the strings, and PIVOT for displaying the parts in their own columns.
WITH Table1 (id, name) AS (
SELECT 1, '1-aaa-14 milan road' UNION ALL
SELECT 2, '23-abcde-lsd road' UNION ALL
SELECT 3, '2-mnbvcx-welcoome street'
),
cutpositions AS (
SELECT
id, name,
rownum = 1,
startpos = 1,
nextdash = CHARINDEX('-', name + '-')
FROM Table1
UNION ALL
SELECT
id, name,
rownum + 1,
nextdash + 1,
CHARINDEX('-', name + '-', nextdash + 1)
FROM cutpositions c
WHERE nextdash < LEN(name)
)
SELECT
id,
[1] AS name,
[2] AS name1,
[3] AS name2
/* add more columns here */
FROM (
SELECT
id, rownum,
part = SUBSTRING(name, startpos, nextdash - startpos)
FROM cutpositions
) s
PIVOT ( MAX(part) FOR rownum IN ([1], [2], [3] /* extend the list here */) ) x
Without additional modifications this query can split names consisting of up to 100 parts (that's the default maximum recursion depth, which can be changed), but can only display no more than 3 of them. You can easily extend it to however many parts you want it to display, just follow the instructions in the comments.
select T.id,
substring(T.Name, 1, D1.Pos-1) as Name,
substring(T.Name, D1.Pos+1, D2.Pos-D1.Pos-1) as Name1,
substring(T.Name, D2.Pos+1, len(T.name)) as Name2
from Table1 as T
cross apply (select charindex('-', T.Name, 1)) as D1(Pos)
cross apply (select charindex('-', T.Name, D1.Pos+1)) as D2(Pos)
Testing performance of suggested solutions
Setup:
create table Table1
(
id int identity primary key,
Name varchar(50)
)
go
insert into Table1
select '1-aaa-14 milan road' union all
select '23-abcde-lsd road' union all
select '2-mnbvcx-welcoome street'
go 10000
Result:
if you always will have 2 dashes, you can do the following by using PARSENAME
--testing table
CREATE TABLE #test(id INT, NAME VARCHAR(1000))
INSERT #test VALUES(1, '1-aaa-14 milan road')
INSERT #test VALUES(2, '23-abcde-lsd road')
INSERT #test VALUES(3, '2-mnbvcx-welcoome street')
SELECT id,PARSENAME(name,3) AS name,
PARSENAME(name,2) AS name1,
PARSENAME(name,1)AS name2
FROM (
SELECT id,REPLACE(NAME,'-','.') NAME
FROM #test)x
if you have dots in the name column you have to first replace them and then replace them back to dots in the end
example, by using a tilde to substitute the dot
INSERT #test VALUES(3, '5-mnbvcx-welcoome street.')
SELECT id,REPLACE(PARSENAME(name,3),'~','.') AS name,
REPLACE(PARSENAME(name,2),'~','.') AS name1,
REPLACE(PARSENAME(name,1),'~','.') AS name2
FROM (
SELECT id,REPLACE(REPLACE(NAME,'.','~'),'-','.') NAME
FROM #test)x
I'm trying to anonymize all the data in my database, so I'm renaming all the people in it. I asked a similar question earlier, and was told to use NewID to force the creation of a new value per updated row, but in this situation it doesn't seem to be working.
What am I doing wrong?
-- Create Table Customer
CREATE TABLE #FirstName
(
ID int,
FirstName nvarchar(255) NULL,
Gender nvarchar(255) NULL
)
CREATE TABLE #LastName (
ID int,
LastName nvarchar(255)
)
-- BULK INSERT to import data from Text or CSV File
BULK INSERT #FirstName
FROM 'C:\Users\jhollon\Desktop\tmp\names\firstnames.lined.txt'
WITH
(
FIRSTROW = 1,
FIELDTERMINATOR = ',',
ROWTERMINATOR = '\n'
)
BULK INSERT #LastName
FROM 'C:\Users\jhollon\Desktop\tmp\names\lastnames.lined.txt'
WITH
(
FIRSTROW = 1,
FIELDTERMINATOR = ',',
ROWTERMINATOR = '\n'
)
/*SELECT FirstName FROM #FirstName WHERE ID = (
SELECT RandomNumber FROM (
SELECT ABS(CHECKSUM(NewID())) % 1500 AS RandomNumber FROM tblTenant WHERE Sex = '1'
) AS A
);*/
UPDATE tblTenant SET TenantName = (
SELECT LastName + ', ' + FirstName FROM
(SELECT UPPER(FirstName) as FirstName FROM #FirstName WHERE ID = (SELECT ABS(CHECKSUM(NewID())) % 500 + 1501)) AS A,
(SELECT LastName FROM #LastName WHERE ID = (SELECT ABS(CHECKSUM(NewID())) % 200 + 1)) as B
) WHERE Sex = '2';
UPDATE tblTenant SET TenantName = (
SELECT LastName + ', ' + FirstName FROM
(SELECT UPPER(FirstName) as FirstName FROM #FirstName WHERE ID = (SELECT ABS(CHECKSUM(NewID())) % 500 + 1)) AS A,
(SELECT LastName FROM #LastName WHERE ID = (SELECT ABS(CHECKSUM(NewID())) % 200 + 1)) as B
) WHERE Sex = '1';
DROP TABLE #FirstName;
DROP TABLE #LastName;
Correct. The subquery is evaluated once which is as advertised ("cachable scalar subquery")
Try this which uses NEWID as a derived table
UPDATE T
SET
TenantName = L.LastName + ', ' + F.FirstName
FROM
tblTenant T
CROSS APPLY
(SELECT TOP 1 UPPER(FirstName) as FirstName FROM #FirstName
WHERE CHECKSUM(NEWID()) <> T.ID
ORDER BY NEWID()) F
CROSS APPLY
(SELECT TOP 1 LastName FROM #LastName
WHERE CHECKSUM(NEWID()) <> T.ID
ORDER BY NEWID()) L
I'm not sure I understand your question, but if you want the ID to be unique values, you can make it an identity column.
Ex:
[ID] [int] IDENTITY(1,1) NOT NULL
The code below demonstrates that without an inner to outer correlation, that the old name is not guaranteed to differ from the new name when using the CROSS APPLY answer above.
WHERE F.Id <> T.Id ORDER BY NEWID() would be better within the FirstName CROSS APPLY
USE tempdb
GO
IF OBJECT_ID('tblTenant') IS NOT NULL
DROP TABLE tblTenant
GO
CREATE TABLE tblTenant
(
Id int,
FirstName nvarchar(20),
LastName nvarchar(20),
Gender bit
)
INSERT INTO tblTenant
VALUES (1, 'Bob' , 'Marley', 1),
(2, 'Boz' , 'Skaggs', 1)
SELECT DISTINCT FirstName
INTO #FirstNames
FROM tblTenant
SELECT DISTINCT LastName
INTO #LastNames
FROM tblTenant
-- There is a probability > 0 that a tenant's new name = tenants old name
SELECT
OldFirst = T.FirstName,
OldLast = T.LastName,
NewFirst = F.FirstName,
NewLast = L.LastName
FROM
tblTenant T
CROSS APPLY
(
SELECT TOP 1 UPPER(FirstName) AS FirstName
FROM #FirstNames
WHERE CHECKSUM(NEWID()) <> T.ID
ORDER BY NEWID()
) F
CROSS APPLY
(
SELECT TOP 1 LastName
FROM #LastNames
WHERE CHECKSUM(NEWID()) <> T.ID
ORDER BY NEWID()
) L