I have two tables in my database. From the Table B i collect some data. I include by using JOIN the data from Table A. In this table there is a column user_id. The user id in table B is the the id from Table A. No i want to get all data from table A but without showing data if the table A id is in the table B column user_id available. I think the trick is the correct usage of JOIN but i need to check the whole column and not just one line.
SQL Query (which is probably not working)
SELECT * FROM tableB
JOIN tableA
ON tableB.user_id = tableA.id
WHERE tableB.user_id != tableA.id
Please see my example i have prepared in Excel:
To select all the data from tableA where id is not available in tableB you don't need join rather you can use not exists or not in.
I would prefer not exists
Using not exists:
SELECT * from tableA a
WHERE NOT EXISTS (
SELECT 1
FROM tableB b
WHERE b.user_id = a.id
);
using not in:
SELECT * from tableA a
WHERE id not in (SELECT user_id FROM tableB );
DB-Fiddle:
create table TableA (id int, name varchar(50), lastname varchar(50));
insert into TableA values(1,'john','smith');
insert into TableA values(2,'Paul','smith');
create table TableB (id int, user_id int, something varchar(50));
insert into TableB values(1,2,'bla');
insert into TableB values(2,3,'bla');
Query: (using not exists)
SELECT * from tableA a
WHERE NOT EXISTS (
SELECT 1
FROM tableB b
WHERE b.user_id = a.id
);
Output:
id
name
lastname
1
john
smith
Query: (using not in)
SELECT * from tableA
WHERE id not in (SELECT user_id FROM tableB );
Output:
id
name
lastname
1
john
smith
db<fiddle here
I think I get what you want. You want not exists:
SELECT *
FROM tableB b JOIN
tableA a
ON b.user_id = a.id
WHERE NOT EXISTS (SELECT 1
FROM tableA a2
WHERE b.user_id = a2.id
);
EDIT:
I wrote the above, but I didn't fully follow the JOIN conditions. You either seem to want to join on id:
SELECT *
FROM tableB b JOIN
tableA a
ON b.id = a.id
WHERE NOT EXISTS (SELECT 1
FROM tableA a2
WHERE b.user_id = a2.id
);
Or no JOIN at all:
SELECT *
FROM tableB b
WHERE NOT EXISTS (SELECT 1
FROM tableA a2
WHERE b.user_id = a2.id
);
Need your help to know if possible to select values from a table with the below condition :
Table content : matching between 2 objects
(Id_obj_A; name_obj_A; country_obj_A; Id_obj_B; name_obj_B; country_obj_B)
Select *
from table
Where (only if country_obj_A <> country_obj_B)
Many thanks for your help
Yes. There are a few ways, one is to use NOT EXISTS like this:
select
*
from tableA
where NOT EXISTS (
select NULL
from tableB
where tableB.country_obj_B = tableA.country_obj_A
)
or, using NOT IN
select
*
from tableA
where country_obj_A NOT IN (
select country_obj_B
from tableB
)
or, using a LEFT JOIN then exclude the joined rows:
select
*
from tableA
left join tableB on tableA.country_obj_A = tableB.country_obj_B
where tableB.country_obj_B IS NULL
I want to find new, modified and deleted records in one table (tableA) by comparing it to another table (tableB). Both tables are of the same schema and has a unique ID field.
In my situation, tableA is originally the same as tableB but it has been edited by some external organisation and once they have done their edits, they send the table back via ZIP file, and we re-populate (truncate and insert) that data to tableA. So I want to find out what records have changed in tableA. I am using SQL Server 2012.
I can get new and modified records with the "except" keyword:
select * from tableA
except
select * form tableB
(Let's call the above results ResultsA)
I can also get deleted and modified records:
select * from tableB
except
select * form tableA
(Let's call the above results ResultsB)
The problem is, both ResultsA and ResultsB have the same records that have been modified/edited. So the modified/edited records are doubled up. I can use inner join or intersect on ResultsA and ResultsB to get just the modified records (call this results ResultsC). But then I will need to use join/except again between ResultsA and ResultsC to get just the new records, and join/except again between ResultsB and ResultsC to get just the deleted records... I tried this and this but they are not working for me.
Obviously this is not good. Are there any elegant and simpler ways to find out the records that have been deleted, modified or added in tableA compared to tableB?
How about:
-- DELETED
SELECT B.*, 'DELETED' AS 'CHANGE_TYPE'
FROM TableB B
LEFT JOIN TableA A ON B.PK_ID = A.PK_ID
WHERE A.PK_ID IS NULL
UNION
-- NEW
SELECT A.*, 'NEW' AS 'CHANGE_TYPE'
FROM TableA A
LEFT JOIN TableB B ON B.PK_ID = A.PK_ID
WHERE B.PK_ID IS NULL
UNION
-- MODIFIED
SELECT B.*, 'MODIFIED' AS 'CHANGE_TYPE'
FROM (
SELECT * FROM TableA
EXCEPT
SELECT * FROM TableB
) S1
INNER JOIN TableB B ON S1.PK_ID = B.PK_ID;
Not exactly elegant, but it works.
Based on what i understood i came up with the following solution.
DECLARE #tableA TABLE (ID INT, Number INT)
DECLARE #tableB TABLE (ID INT, Number INT)
INSERT INTO #tableA VALUES
(1,10),
(2,20),
(3,30),
(4,40)
INSERT INTO #tableB VALUES
(1,11),
(2,20),
(4,40),
(5,50)
SELECT *,'Modified or deleted' as 'Status' FROM
(
select * from #tableA
except
select * from #tableB
)a WHERE ID NOT IN
(
select ID from #tableB
except
select ID from #tableA
)
UNION
SELECT *,'New' as 'Status' FROM
(
select * from #tableB
except
select * from #tableA
)b WHERE ID NOT IN
(
SELECT ID FROM
(
select * from #tableA
except
select * from #tableB
)a WHERE ID NOT IN
(
select ID from #tableB
except
select ID from #tableA
)
)
You can use the OUTPUT clause:
Returns information from, or expressions based on, each row affected by an INSERT, UPDATE, or DELETE statement. These results can be returned to the processing application for use in such things as confirmation messages, archiving, and other such application requirements. Alternatively, results can be inserted into a table or table variable.
See the the following, sorry I don't have a practical code for you. But note the SQL output clause can be used to return any value from ‘inserted’ and ‘deleted’ (New value and Old value) tables when doing an insert or update. follow this for more info
declare #DBOrderItem table
(
OrderItemGuid UniqueIdentifier default newid(),
Name VarChar(100)
);
declare #PayloadOrderItem table
(
OrderItemGuid UniqueIdentifier default newid(),
Name VarChar(100)
);
insert into #DBOrderItem (Name) values ('Phone');
insert into #DBOrderItem (Name) values ('Laptop');
insert into #PayloadOrderItem
select top 1 * from #DBOrderItem;
insert into #PayloadOrderItem (Name) values ('Tablet');
select doi.OrderItemGuid,
doi.Name,
case when poi.OrderItemGuid is null then 'Delete' else 'Update' end ActionType
from #DBOrderItem doi
left join #PayloadOrderItem poi on doi.OrderItemGuid = poi.OrderItemGuid
union
select poi.OrderItemGuid,
poi.Name,
'Add' ActionType
from #PayloadOrderItem poi
left join #DBOrderItem doi on doi.OrderItemGuid = poi.OrderItemGuid
where doi.OrderItemGuid is null;
Another solution that works quite efficiently is to use a where not exists an intersect between the two tables. Its very compact.
SELECT
IsNull(tableB.ID,tableA.ID) as 'ID',
IsNull(tableB.Number,tableA.Number) as 'Number',
'Action' = CASE
WHEN tableB.ID IS NULL THEN 'Deleted'
WHEN tableA.ID IS NULL THEN 'Created'
ELSE 'Updated'
END
FROM tableA
FULL OUTER JOIN tableB
ON tableB.ID = tableA.ID
WHERE
NOT EXISTS (SELECT tableB.* INTERSECT SELECT tableA.*)
This keeps the table scans down to a minimum, and provides detection of new, deleted and changed records.
I put all three from here into fiddle, and its surprising how differently they all compile.
http://sqlfiddle.com/#!6/b1a5a/5
This one works without primary key also a bit more elegant .(in my opinion!)
WITh A AS (SELECT 1,2,3 FROM DUAL
UNION ALL
SELECT 1,3,2 FROM DUAL
UNION ALL
SELECT 1,3,1 FROM DUAL),
B AS (SELECT 1,3,2 FROM DUAL
UNION ALL
SELECT 1,2,3 FROM DUAL
UNION ALL
SELECT 1,3,5 FROM DUAL
)
,
C AS
(SELECT * FROM A
MINUS
SELECT * FROM B
),
D AS( SELECT * FROM b
MINUS
SELECT * FROM A)
SELECT C.* ,'Deleted' FROM c
UNION ALL
SELECT D.* ,'Added' FROM D
I will like to drop an existing table and insert new records from a select statement. Keeping the coulmns the same. Old table (column a, column b) and select statment (select from a,b,c,d with inner joins)
If you need to drop completely you can do this:
Drop table yourtable
SELECT *
INTO yourtable
FROM
(SELECT a , b FROM blah, blah) x
Unless you want to change the schema of your old table, you might try a TRUNCATE TABLE:
TRUNCATE TABLE MyTable
Then you can insert into this table with a SELECT:
INSERT INTO MyTable
(
ColumnA,
ColumnB,
...
)
SELECT
ValueA,
ValueB,
...
FROM
Table1
INNER JOIN Table2
ON Table2.SomeColumn = Table1.SomeColumn
...
On the other hand, if you really want to recreate the table, then you can DROP TABLE and re-create it with a SELECT INTO as Jayvee showed.
I have two tables
Table A:
ID
1
2
3
4
Table B:
ID
1
2
3
I have two requests:
I want to select all rows in table A that table B doesn't have, which in this case is row 4.
I want to delete all rows that table B doesn't have.
I am using SQL Server 2000.
You could use NOT IN:
SELECT A.* FROM A WHERE ID NOT IN(SELECT ID FROM B)
However, meanwhile i prefer NOT EXISTS:
SELECT A.* FROM A WHERE NOT EXISTS(SELECT 1 FROM B WHERE B.ID=A.ID)
There are other options as well, this article explains all advantages and disadvantages very well:
Should I use NOT IN, OUTER APPLY, LEFT OUTER JOIN, EXCEPT, or NOT EXISTS?
For your first question there are at least three common methods to choose from:
NOT EXISTS
NOT IN
LEFT JOIN
The SQL looks like this:
SELECT * FROM TableA WHERE NOT EXISTS (
SELECT NULL
FROM TableB
WHERE TableB.ID = TableA.ID
)
SELECT * FROM TableA WHERE ID NOT IN (
SELECT ID FROM TableB
)
SELECT TableA.* FROM TableA
LEFT JOIN TableB
ON TableA.ID = TableB.ID
WHERE TableB.ID IS NULL
Depending on which database you are using, the performance of each can vary. For SQL Server (not nullable columns):
NOT EXISTS and NOT IN predicates are the best way to search for missing values, as long as both columns in question are NOT NULL.
select ID from A where ID not in (select ID from B);
or
select ID from A except select ID from B;
Your second question:
delete from A where ID not in (select ID from B);
SELECT ID
FROM A
WHERE NOT EXISTS( SELECT 1
FROM B
WHERE B.ID = A.ID
)
This would select 4 in your case
SELECT ID FROM TableA WHERE ID NOT IN (SELECT ID FROM TableB)
This would delete them
DELETE FROM TableA WHERE ID NOT IN (SELECT ID FROM TableB)
SELECT ID
FROM A
WHERE ID NOT IN (
SELECT ID
FROM B);
SELECT ID
FROM A a
WHERE NOT EXISTS (
SELECT 1
FROM B b
WHERE b.ID = a.ID)
SELECT a.ID
FROM A a
LEFT OUTER JOIN B b
ON a.ID = b.ID
WHERE b.ID IS NULL
DELETE
FROM A
WHERE ID NOT IN (
SELECT ID
FROM B)