I have two tables both with one column each. I want to copy/merge the data from those two tables into another table with both columns. So in the example below I want the data from Table1 and Table2 to go into Table3.
I used this query:
INSERT **TABLE3** (BIGNUMBER)
SELECT BIGNUMBER
FROM **TABLE1**;
INSERT **TABLE3** (SMALLNUMBER)
SELECT SMALLNUMBER
FROM **TABLE2**;
When I did this it copied the data from Table1 and Table2 but didn't put the data on the same lines. So it ended up like this:
I am trying to get the data to line up... match. So BIGNUMBER 1234567812345678 should have SMALLNUMBER 123456 next to it. If I am querying I could do this with a JOIN and a LIKE 'SMALLNUMBER%' but I am not sure how to do that here to make the data end up like this:
It doesn't have to be fancy comparing the smallnumber to the bignumber. When I BULK insert data into TABLE1 and TABLE2 they are in the same order so simply copying the data into TABLE3 without caring if SMALL is the start of BIG is fine with me.
There is no relationship at all in these tables. This is the simplest form I can think of. Basically two flat tables that need to be merged side by side. There is no logic to implement... start at row 1 and go to the end on BIGNUMBER. Start at row 1 again and go to the end on SMALLNUMBER. All that matters is if BIGBUMBER has 50 rows and SMALLNUMBER has 50 rows, in the end, there is still only 50 rows.
When I was using the query above I was going off of a page I was reading on MERGE. Now that I look over this I don't see MERGE anywhere... so maybe I just need to understand how to use MERGE.
If the order of numbers is not important and you don't want to add another field to your source tables as jcropp suggested, you can use ROW_NUMBER() function within a CTE to align a number to each row and then make a join based on them
WITH C1 AS(
SELECT ROW_NUMBER() OVER (ORDER BY TABLE1.BIGNUMBER) AS Rn1
,BIGNUMBER
FROM TABLE1
)
,C2 AS(
SELECT ROW_NUMBER() OVER (ORDER BY TABLE2.SMALLNUMBER) AS Rn2
,SMALLNUMBER
FROM TABLE2
)
INSERT INTO TABLE3
SELECT C1.BIGNUMBER
,C2.SMALLNUMBER
FROM C1
INNER JOIN C2 ON C1.Rn1 = C2.Rn2
More information about ROW_NUMBER(), CTE and INSERT INTO SELECT
In order to use a JOIN statement to merge the two tables they each have to have a column that has common data. You don’t have that, but you may be able to introduce it:
Edit the structure of the first table. Add a column named something
like id and set the attributes of the id column to autonumber.
Browse the table to make sure that theid column has been assigned
numbers in the correct order.
Do the same for the second table.
After you’ve done a thorough check to ensure that the rows are
numbered correctly, run a query to merge the tables:
SELECT TABLE1.id, TABLE1.BIGNUMBER, TABLE2.SMALLNUMBER INTO TABLE3
FROM TABLE1 INNER JOIN TABLE2 ON TABLE1.id = TABLE2.id
Related
I have something to fix in my database here it is:
I have a table with duplicate rows like that:
the duplicate columns are IDPatient and IDObjet and you should never have both duplicate and that's why i put Key on both column but it's a bit too late.. so I have to fix this by combining these duplicate row into one without losing data and to put it in order.
Example, as you can see in the picture the column texte_1 contains each one a date 2010-11-25 and 2011-11-04. The date 2010-11-25 come before 2011-11-04 So i have to put 2011-11-04 into the column texte_2 of the first row and looping like that for each data I have in my row and to verify if the date is older or not. If yes, I have to replace the data in the row one with the second row, taking the information we have replace in a temp var and then finding a new column("Texte_X") to insert into the same row my replace data and validating at the same time if it's not older.
I can have multiple duplicate row in my table and I know looping in SQL server is slow, but would really appreciate a good solution to solve this here.
Here's a example of multiple duplicate row
How about a MERGE:
merge mytable as t
using (
select idPatient, idObject, max(texte_1) dt
from mytable
group by idPatient, idObject
) s on t.idPatient = s.idPatient
and t.idObject = s.idObject
and t.texte_1 != s.dt
when matched then delete;
You could use the ROW_NUMBER() function and your ID field to order the duplicates, then PIVOT to de-normalize the records, or self-joins, like:
;with cte as (SELECT *,RN = ROW_NUMBER() OVER(PARTITION BY IDPatient,IDObjet ORDER BY ID)
FROM YourTable
)
SELECT a.IDPatient,a.IDObjet,a.Texte_1, b.Texte_1 as Texte_2, c.Texte_1 AS Texte_3
FROM cte a
LEFT JOIN cte b
ON a.IDPatient = b.IDPatient
AND a.IDObjet = b.IDObjet
AND b.RN = 2
LEFT JOIN cte c
ON a.IDPatient = c.IDPatient
AND a.IDObjet = c.IDObjet
AND c.RN = 3
WHERE a.RN = 1
This assumes the ID order is sufficient, you could change it to your date field if needed. Since you ultimately want to remove the duplicate lines, you could either run this query into a new table, or after you use this as the basis of your update you can then DELETE records from the cte above where RN > 1
Personally, I would avoid the de-normalized Texte_1-10 structure, and add a new field that's the equivalent of the RN field as part of the key.
Hypothetically I want to merge 2 tables from different databases into one table, which includes all the data from the 2 tables:
The result would look like something like this:
Aren't the entries in the result table redundant, because there are 2 entries with Porsche and VW? Or can I just add the values in the column 'stock' because the column 'Mark' is explicit?
you need to create database link to another database here is the example on how to create database link http://psoug.org/definition/create_database_link.htm
after creating your select statement from another database should look: select * from tableA#"database_link_name"
Then you need to use MERGE statement to push data from another database so the merge statement should look something like this.
you can read about merge statement here: https://docs.oracle.com/cd/B28359_01/server.111/b28286/statements_9016.htm#SQLRF01606
merge into result_table res
using (select mark, stock, some_unique_id
from result_table res2
union all
select mark, stock, some_unique_id
from tableA#"database_link_name") diff
on (res.some_unique_id = diff.some_unique_id )
when matched then
update set res.mark = diff.mark,
res.stock = diff.stock
when not matched then
insert
(res.mark,
res.stock,
res.some_unique_id)
values
(diff.mark,
diff.stock,
diff.some_unique_id);
I hope this will help you
SELECT ROW_NUMBER() OVER (ORDER BY Mark) AS new_ID, Mark, SUM(Stock) AS Stock
FROM
(
SELECT Mark,Stock FROM Database1.dbo.table1
UNION ALL
SELECT Mark,Stock FROM Database2.dbo.table2
) RESULT
GROUP BY Mark
Try this:
Select Mark, Stock, row_number() over(order by Mark desc) from table1
union all
Select Mark, Stock, row_number() over(order by Mark desc) from table2
regardless of the data redundancy, you could use union all clause to achieve this. Like:
Select * From tableA
UNION ALL
Select * From tanleB
Make sure the total number of columns and datatype should be matched between each
Don't forget to use fully qualified table names as the tables are in different databases
SELECT
Mark
,Stock
FROM Database1.dbo.table1
UNION ALL
SELECT
Mark
,Stock
FROM Database2.dbo.table2
If these are 2 live databases and you would need to constantly include rows from the 2 databases into your new database consider writing the table in your 3rd database as a view rather.
This way you can also add a column specifying which system the datarow is coming from. Summing the values is an option, however if you ever have a query regarding a incorrect summed value how would you know which system is the culprit?
While trying to merge two tables, when rows not matched how do I insert rows based on an order. For example in table_2 I have a column "Type" (sample values 1,2,3 etc), so when I do an insert for unmatched codes I need to insert records with type as 1 first, then 2 etc.
So far I tried below code
WITH tab1 AS
(
select * From TABLE_2 order by Type
)
merge tab1 as Source using TABLE_1 as Target on Target.Code=Source.Code
when matched then update set Target.Description=Source.Description
when not matched then insert (Code,Description,Type)
values (Source.Code,Source.Description,Source.Type);
But I get "The ORDER BY clause is invalid in views, inline functions, derived tables, subqueries, and common table expressions, unless TOP or FOR XML is also specified." error because of using order by in sub query.
So how do I insert records based on an order while merging two table?
Thanks in advance.
Change
select *
to
select top 100 percent
That will allow you to use ORDER BY in the first select
Suppose I have a table with lots of rows identified by a unique ID. Now I have a (rather large) user-input list of ids (not a table) that I want to check are already in the database.
So I want to output the ids that are in my list, but not in the table. How do I do that with SQL?
EDIT: I know I can do that with a temporary table, but I'd really like to avoid that if possible.
EDIT: Same comment for using an external programming language.
Try with this:
SELECT t1.id FROM your_list t1
LEFT JOIN your_table t2
ON t1.id = t2.id
WHERE t2.id IS NULL
It is hardly possible to make a single pure and general SQL query for your task, since it requires to work with a list (which is not a relational concept and standard set of list operations is too limited). For some DBMSs it is possible to write a single SQL query, but it will utilize SQL dialect of the DBMS and will be specific to the DBMS.
You haven't mentioned:
which RDBMS will be used;
what is the source of the IDs.
So I will consider PostgreSQL is used, and IDs to be checked are loaded into a (temporary) table.
Consider the following:
CREATE TABLE test (id integer, value char(1));
INSERT INTO test VALUES (1,'1'), (2,'2'), (3,'3');
CREATE TABLE temp_table (id integer);
INSERT INTO temp_table VALUES (1),(5),(10);
You can get your results like this:
SELECT * FROM temp_table WHERE NOT EXISTS (
SELECT id FROM test WHERE id = temp_table.id);
or
SELECT * FROM temp_table WHERE id NOT IN (SELECT id FROM test);
or
SELECT * FROM temp_table LEFT JOIN test USING (id) WHERE test.id IS NULL;
You can pick any option, depending on your volumes you may have different performance.
Just a note: some RDBMS may have limitation on the number of expressions specified literally inside IN() construct, keep this in mind (I hit this several times with ORACLE).
EDIT: In order to match constraints of no temp tables and no external languages you can use the following construct:
SELECT DISTINCT b.id
FROM test a RIGHT JOIN (
SELECT 1 id UNION ALL
SELECT 5 UNION ALL
SELECT 10) b ON a.id=b.id
WHERE a.id IS NULL;
Unfortunately, you'll have to generate lot's of SELECT x UNION ALL entries to make a single-column and many-rows table here. I use UNION ALL to avoid unnecessary sorting step.
I want to check my database for records that I already have recorded before making a web service call.
Here is what I imagine the query to look like, I just can't seem to figure out the syntax.
SELECT *
FROM (1,2,3,4) as temp_table
WHERE temp_table.id
LEFT JOIN table ON id IS NULL
Is there a way to do this? What is a query like this called?
I want to pass in a list of id's to mysql and i want it to spit out the id's that are not already in the database?
Use:
SELECT x.id
FROM (SELECT #param_1 AS id
FROM DUAL
UNION ALL
SELECT #param_2
FROM DUAL
UNION ALL
SELECT #param_3
FROM DUAL
UNION ALL
SELECT #param_4
FROM DUAL) x
LEFT JOIN TABLE t ON t.id = x.id
WHERE x.id IS NULL
If you need to support a varying number of parameters, you can either use:
a temporary table to populate & join to
MySQL's Prepared Statements to dynamically construct the UNION ALL statement
To confirm I've understood correctly, you want to pass in a list of numbers and see which of those numbers isn't present in the existing table? In effect:
SELECT Item
FROM IDList I
LEFT JOIN TABLE T ON I.Item=T.ID
WHERE T.ID IS NULL
You look like you're OK with building this query on the fly, in which case you can do this with a numbers / tally table by changing the above into
SELECT Number
FROM (SELECT Number FROM Numbers WHERE Number IN (1,2,3,4)) I
LEFT JOIN TABLE T ON I.Number=T.ID
WHERE T.ID IS NULL
This is relatively prone to SQL Injection attacks though because of the way the query is being built. It'd be better if you could pass in '1,2,3,4' as a string and split it into sections to generate your numbers list to join against in a safer way - for an example of how to do that, see http://www.sqlteam.com/article/parsing-csv-values-into-multiple-rows
All of this presumes you've got a numbers / tally table in your database, but they're sufficiently useful in general that I'd strongly recommend you do.
SELECT * FROM table where id NOT IN (1,2,3,4)
I would probably just do:
SELECT id
FROM table
WHERE id IN (1,2,3,4);
And then process the list of results, removing any returned by the query from your list of "records to submit".
How about a nested query? This may work. If not, it may get you in the right direction.
SELECT * FROM table WHERE id NOT IN (
SELECT id FROM table WHERE 1
);