Updating one column in Oracle - database

I have an Oracle table which contains a column called dt_code, first_name, last_name, and user_id. I need to update dt_code with a list of codes that was given to me in an excel file. What would be the best way to update the column and maintain the relationships.

as simple as
update your_table
set dt_code = new_code
where id = specific_id;
this won't break any relationships.
Note that Oracle allow you to import xls datas, but since I have no idea of your syntax it is hard to tell you how to do it.
If there is a lot of update to do, you should import all the datas in a temporary table, then do the update based on this table.
If you choose this option and you are not used to this kind of update statement, have a look at this thread Update statement with inner join on Oracle.

Related

Merge query using two tables in SQL server 2012

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.

Copy table data and populate new columns

So I'm trying to copy some data from database table to another. The problem is though, the target database table has 2 new columns that are required. I wanted to use the export/import wizard on SQL Server Management Studio but if I use that I will need to write a query for each table and I can only execute 1 query at a time. Was wondering if there are a more efficient way of doing it.
Here's an example of 1 table:
dbase1.dbo.Appointment { id, name, description, createdate }
dbase2.dbo.Appointment { id, name, description, createdate, auditby, auditat}
I have a total of 8 tables with those 2 additional columns. and most of them are related to each other via fk, so I wanted to use the wizard as it figures out which table gets inserted first. The problem with that is, it only works if I do a "copy data from one or more tables " and not the "write a query to specify data" (I use this to populate those two new columns).
I've been doing this very slow process in copying data as I'm using MVC Code First for my application and I dont have access to the server to be able to drop and create the table at my leisure. So I have to resort to this to maintain the data that I already have.
An idea: temporarily disable the foreign key constraints in the destination database. Then it doesn't matter what order you run your inserts. In order to populate the two new and required columns, you just need to pick some stock values to put in there (since obviously these rows initially are not subject to initial auditing). For example:
INSERT dbase2.dbo.appointment
(id, name, description, createdate, auditby, auditat)
SELECT id, name, description, createdate,
auditby = 'me', auditat = GETDATE()
FROM dbo.appointment;
Since it seems the challenge is merely that the destination requires columns that aren't in the source, and that you need to determine what should be populated in these audit columns, this seems to solve multiple problems at once. You just need to figure out what to put in there instead of 'me' and GETDATE().
(To get the wizard to pull these 8 tables for you, you might be able to create a view similar to the select portion of the above query, but that's more work and it won't see the underlying FK constraints to generate them in the right order anyway.)
Write the sql query for each of the insert processes in the order you want it. That would be the simplest approach.
Set the Default values for these two columns
Like for AuditAt - Default Date i.e. GetDate()
For AuditBy - The Person ID/Name
Now, you can Insert into these tables without entering for these two columns

Using Triggers in SQL Server to keep a history

I am using SQL Server 2012
I have a table called AMOUNTS and a table called AMOUNTS_HIST
Both tables have identical columns:
CHANGE_DATE
AMOUNT
COMPANY_ID
EXP_ID
SPOT
UPDATE_DATE [system date]
The Primary Key of AMOUNTS is COMPANY_ID and EXP_ID.
The Primary Key pf AMOUNTS_HIST is COMPANY_ID, EXP_ID and CHANGE_DATE
Whenever I add a row in the AMOUNTS table, I would like to create a copy of it in the AMOUNTS_HIST table. [Theoretically, each time a row is added to 'AMOUNTS', the COMPANY_ID, EXP_ID, CHANGE_DATE will be unique. Practically, if they are not, the relevant row in AMOUNTS_HIST would need to be overridden. The code below does not take the overriding into account.]
I created a trigger as follows:
CREATE TRIGGER [MYDB].[update_history] ON [MYDB].[AMOUNTS]
FOR UPDATE
AS
INSERT MYDB.AMOUNTS_HIST (
CHANGE_DATE,
COMPANY_ID,
EXP_ID,
SPOT
UPDATE_DATE
)
SELECT e.CHANGE_DATE,
e.COMPANY_ID,
e.EXP_ID
e.REMARKS,
e.SPOT,
e.UPDATE_DATE
FROM MYDB.AMOUNTS e
JOIN inserted ON inserted.company_id = e.company_id
AND inserted.exp_id=e.exp_id
I don't understand why it does nothing at all in my AMOUNTS_HIST table.
Can anyone help?
Thanks,
Probably because the trigger, the way it's currently written, will only get fired when an Update is done, not an insert.
Try changing it to:
CREATE TRIGGER [MYDB].[update_history] ON [MYDB].[AMOUNTS]
FOR UPDATE, INSERT
I just wanted to chime in. Have you looked at CDC (change data capture).
http://msdn.microsoft.com/en-us/library/bb522489(v=sql.105).aspx
"Change data capture is designed to capture insert, update, and delete activity applied to SQL Server tables, and to make the details of the changes available in an easily consumed relational format. The change tables used by change data capture contain columns that mirror the column structure of a tracked source table, along with the metadata needed to understand the changes that have occurred.
Change data capture is available only on the Enterprise, Developer, and Evaluation editions of SQL Server."
As far as your trigger goes, when you update [MYDB].[AMOUNTS] does the trigger throw any errors?
Also I believe you can get all your data from Inserted table without needed to do the join back to mydb.amounts.

Populating a table with fields from two other tables

I have two tables in Filemaker:
tableA (which includes fields idA (e.g. a123), date, price) and
tableB (which includes fields idB (e.g. b123), date, price).
How can I create a new table, tableC, with field id, populated with both idA and idB, (with the other fields being used for calculations on the combined data of both tables)?
The only way is to script it (for repeating uses) or do it 'manually', if this is an ad-hoc process. Details depend on the situation, so please clarify.
Update: Sorry, I actually forgot about the question. I assume the ID fields do not overlap even across tables and you do not need to add the same record more than once, but update it instead. In such a case the simplest script would be like that:
Set Variable[ $self, Get( FileName ) ]
Import Records[ $self, Table A -> Table C, sync on ID, update and add new ]
Import Records[ $self, Table B -> Table C, sync on ID, update and add new ]
The Import Records step is managed via rather elaborate dialog, but the idea is that you import from the same file (you can just type file:<YourFileName> there), the format is FileMaker Pro, and then set the field mapping. Make sure to choose the Update matching records and Add remaining records options and select the ID fields as key files to sync by.
It would be a FileMaker script. It could be run as a script trigger, but then it's not going to be seamless to the user. Your best bet is to create the tables, then just run the script as needed (manually) to build Table C. If you have FileMaker Server, you could schedule this script to be run periodically to keep Table C up-to-date.
Maybe you can use the select into statement.
I'm unsure if you wish to use calculated field from TableA and TableB or if your intension was to only calculate fields from the same table?
If tableA.IdA exists also in tableB.IdA, you could join the two tables and select into.
Else, you run the statement once for each table.
Select into statement
Select tableA.IdA, tableA.field1A, tableA.field2A, tableA.field1A * tableB.field2A
into New_Table from tableA
Edit: missed the part where you mentioned FileMaker.
But maybe you could script this on the db and just drop the table.

table relationships, SQL 2005

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.

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