How can i transfer rows from two tables (Patient and ContactDetails) from DB1 to DB2?
Both DBs, have already these 2 tables with data. i just want to add data from these two tables from db1 to db2.
i tried following that
but it didnt work, because there are some rows with the same keys and overwrite is forbidden.
is there an other way to do it? or am i missing something?
patient and contactdetails relationship is
patient inner join contactdetails
(foreign_key)patient.contactdetailsid = (primary_key)contactdetails.id
loop on the source contactdetails table, insert each row one a time saving in a temp table the old contactdetail id and the matching new contactdetail id (here is an example of sql loop).
the temp table should be something like:
create #temptableforcopy table (
oldcontactdetailsid [insertheretherightdatatype],
newcontactdetailsid [insertheretherightdatatype]
)
copy the data from the patient table joined to the temp table used for the previous step like this:
insert into newdb.newschema.patient (contactdetailsid, field1, field2, ...)
select TT.newcontactdetailsid,
old.field1,
old.field2,
...
from olddb.oldschema.patient old
join #temptableforcopy TT on TT.oldcontactdetailsid = old.contactdetailsid
please note that my proposal is just a wild guess: you gave no information about structure, keys, constraints, no detail about which key is preventing the copy with which error message, the solution you already discarded, the amount of data you have to deal with...
Related
I need to create a routine that regularly checks a database and make changes if necessary.
Let me explain my problem with the following example.
A Database stores participants and winners of tournaments.
We got two tables storing the base data (tournaments, people)
Furthermore we got two more tables for the references.
Winner table that store tournamentId and peopleId
Participant table that stores tournamentId and peopleId
Now the script should take every entry from the winner table and insert it into the participant table because every winner is a participant as well.
Insert Into ParticipantTable
Select * From WinnerTable
However some users of the database insert winners in the participant table manually, some don't.
The code above won't work since PK Violations can appear.
How can I tell the statement to make insertion only if the entry isn't in participant table yet?
Thanks in advance, sorry for my messi english and keep in mind that the example above is fictional I am aware that the described data model doesn't fit perfectly for the described usecase.
Merge?
merge ParticipantTable as trg
using WinnerTable as src on src.pk_col1 = trg.pk_col1
and src.pk_col2 = trg.pk_col2
... /* here is PK columns binding */
when not matched then
insert (col1, col2, col3, ...)
values (src.col1, src.col2, src.col3, ...);
I have an ETL process (CSV to SQL database) that runs daily, but the data in the source sometimes changes, so I want to have it run again the next day with an updated file.
How do I write a SQL statement to find all the differences?
For example, let's say Table_1 has a composite PRIMARY KEY consisting of FK_1, FK_2 and FK_3.
Do I do this in SQL or in the ETL process?
Thanks.
Edit
I realize now this question is too broad. Disregard.
You can use EXCEPT to find which are the IDs which are missing. For example:
SELECT FK_1, FK_2, FK_2
FROM new_data_table
EXCEPT
SELECT FK_1, FK_2, FK_2
FROM current_data_table;
It will be better (in performance prospective) to materialized these IDs and then to join this new table to the new_data_table in order to insert all of the columns.
If you need to do this in one query, you can use simple LEFT JOIN. For example:
INSERT INTO current_data_table
SELECT A.*
FROM new_data_table A
LEFT JOIN current_data_table B
ON A.FK_1 = B.FK_1
AND A.FK_2 = B.FK_2
AND A.FK_3 = B.FK_3
WHRE B.[FK_1] IS NULL;
The idea is to get all records in the new_data_table for which, there is no match in the current_data_table table (WHRE B.[FK_1] IS NULL).
I have here some database schema with tables having long fields (in MS-SQL-Server of type "text", in Sybase of type "text" too) and I need to retrieve distinct rows.
The tables looks like
create table node (id int primary key, … a few more fields … data text);
create table ref (id int primary key, node_id int, … a few more fields);
For one row in "node", there may be zero or more rows in "ref".
Now I have a query like
SELECT node.* FROM node, ref WHERE node.id = ref.node_id AND ... some more restrictions.
This query returns duples and triples when there is more than a single row in "ref" for some "node_id".
But I need unique rows!
Using SELECT DISTINCT node.* does not work because of the columns of type "text" :-(
In Sybase there is trick, just add "GROUP BY node.id" to the query, voila! You get unique rows returned.
Is there some similar simple Trick for MS-SQL-Server?
I have already a solution with temporary tables, but this seems to be a lot slower maybe the reason is just because of the larger number of statements transferred to the database?
It looks like you are approaching this problem from the wrong direction. Joins are typically used to expand on keys where relevant data is stored in different tables. So it's no surprise you are getting more than one row per node_id.
In your query, you join the two tables together, but then you ignore everything from ref. It looks like you're just trying to filter out ids from node that are not referenced in ref. If that is the case, then you don't want to use a join. The following will work much better
select *
from node
where id in (
select node_id
from ref
where [any restrictions placed on the ref table go here]
)
and [any restrictions placed on the node table go here]
Furthermore, at the risk of teaching you bad join practices, the same thing can be accomplished they way you were trying to do it originally, but it's more painful to write and it's not good practice
select node.col1, node.col2, ... , node.last_col
FROM node
inner join ref on node.id = ref.node_id
where [some restrictions.]
group by node.col1, node.col2, ... , node.last_col
I am very new to SQL and SQL server, would appreciate any help with the following problem.
I am trying to update a share price table with new prices.
The table has three columns: share code, date, price.
The share code + date = PK
As you can imagine, if you have thousands of share codes and 10 years' data for each, the table can get very big. So I have created a separate table called a share ID table, and use a share ID instead in the first table (I was reliably informed this would speed up the query, as searching by integer is faster than string).
So, to summarise, I have two tables as follows:
Table 1 = Share_code_ID (int), Date, Price
Table 2 = Share_code_ID (int), Share_name (string)
So let's say I want to update the table/s with today's price for share ZZZ. I need to:
Look for the Share_code_ID corresponding to 'ZZZ' in table 2
If it is found, update table 1 with the new price for that date, using the Share_code_ID I just found
If the Share_code_ID is not found, update both tables
Let's ignore for now how the Share_code_ID is generated for a new code, I'll worry about that later.
I'm trying to use a merge query loosely based on the following structure, but have no idea what I am doing:
MERGE INTO [Table 1]
USING (VALUES (1,23-May-2013,1000)) AS SOURCE (Share_code_ID,Date,Price)
{ SEEMS LIKE THERE SHOULD BE AN INNER JOIN HERE OR SOMETHING }
ON Table 2 = 'ZZZ'
WHEN MATCHED THEN UPDATE SET Table 1.Price = 1000
WHEN NOT MATCHED THEN INSERT { TO BOTH TABLES }
Any help would be appreciated.
http://msdn.microsoft.com/library/bb510625(v=sql.100).aspx
You use Table1 for target table and Table2 for source table
You want to do action, when given ID is not found in Table2 - in the source table
In the documentation, that you had read already, that corresponds to the clause
WHEN NOT MATCHED BY SOURCE ... THEN <merge_matched>
and the latter corresponds to
<merge_matched>::=
{ UPDATE SET <set_clause> | DELETE }
Ergo, you cannot insert into source-table there.
You could use triggers for auto-insertion, when you insert something in Table1, but that will not be able to insert proper Shared_Name - trigger just won't know it.
So you have two options i guess.
1) make T-SQL code block - look for Stored Procedures. I think there also is a construct to execute anonymous code block in MS SQ, like EXECUTE BLOCK command in Firebird SQL Server, but i don't know it for sure.
2) create updatable SQL VIEW, joining Table1 and Table2 to show last most current date, so that when you insert a row in this view the view's on-insert trigger would actually insert rows to both tables. And when you would update the data in the view, the on-update trigger would modify the data.
Ok I have a question and it is probably very easy but I can not find the solution.
I have 3 tables plus one main tbl.
tbl_1 - tbl_1Name_id
tbl_2- tbl_2Name_id
tbl_3 - tbl_3Name_id
I want to connect the Name_id fields to the main tbl fields below.
main_tbl
___________
tbl_1Name_id
tbl_2Name_id
tbl_3Name_id
Main tbl has a Unique Key for these fields and in the other table, fields they are normal fields NOT NULL.
What I would like to do is that any time when the record is entered in tbl_1, tbl_2 or tbl_3, the value from the main table shows in that field, or other way.
Also I have the relationship Many to one, one being the main tbl of course.
I have a feeling this should be very simple but can not get it to work.
Take a look at SQL Server triggers. This will allow you to perform an action when a record is inserted into any one of those tables.
If you provide some more information like:
An example of an insert
The resulting change you would like
to see as a result of that insert
I can try and give you some more details.
UPDATE
Based on your new comments I suspect that you are working with a denormalized database schema. Below is how I would suggest you structure your tables in the Employee-Medical visit scenario you discussed:
Employee
--------
EmployeeId
fName
lName
EmployeeMedicalVisit
--------------------
VisitId
EmployeeId
Date
Cost
Some important things:
Note that I am not entering the
employees name into the
EmployeeMedicalVisit table, just the EmployeeId. This
helps to maintain data integrity and
complies with First Normal Form
You should read up on 1st, 2nd and
3rd normal forms. Database
normalization is a very imporant
subject and it will make your life
easier if you can grasp them.
With the above structure, when an employee visited a medical office you would insert a record into EmployeeMedicalVisit. To select all medical visits for an employee you would use the query below:
SELECT e.fName, e.lName
FROM Employee e
INNER JOIN EmployeeMedicalVisit as emv
ON e.EployeeId = emv.EmployeeId
Hope this helps!
Here is a sample trigger that may show you waht you need to have:
Create trigger mytabletrigger ON mytable
For INSERT
AS
INSERT MYOTHERTABLE (MytableId, insertdate)
select mytableid, getdate() from inserted
In a trigger you have two psuedotables available, inserted and deleted. The inserted table constains the data that is being inserted into the table you have the trigger on including any autogenerated id. That is how you get the data to the other table assuming you don't need other data at the same time. YOu can get other data from system stored procuders or joins to other tables but not from a form in the application.
If you do need other data that isn't available in a trigger (such as other values from a form, then you need to write a sttored procedure to insert to one table and return the id value through an output clause or using scope_identity() and then use that data to build the insert for the next table.