I have to reference information of a table using the PK from another table. For that I have to see if the information matches in a third table.
To better explain, I show you the screenshots the SELECT from the tables I need to use or change.
In the next two screenshot of tables, I have an Address table that contains information about differentes addresses and an "addressid" PK. The next table, is a Company table that provides information about differentes companies. These companies need to have two FKs to the Address table in the two different columns that are empty.
So, I have a table with a lot of mixed information, including the addresses combined with the companies.
Using this "import" tables, I have to set the empty FK on Company table related to the PKs of Address table.
I have tried doing an UPDATE function but I don't really know how to write the conditions to use this "import" table to relate the other two tables.
Thanks on advance.
In the IMPORT table I have all the info in Company table and Address table, but mixed, with other unused information. So, I have for each row in Company, look at the Company name, search it on the import table, look in the same row what is the address, search it on the Address table and put the correspondent PK on the Company table... Example: COMPANY - Google IMPORT - Google California ADDRESS - Californa id1 Go to COMPANY - Google (add id1 on column address)... Sorry if I explain it not so good.
Something like this might work for the shipping address:
update company c
set ordership_address = (select addressid
from address a
inner join import i
on a.addressname = i.ordershipadress
and a.postalcode = i.ordershippostalcode
-- and other criteria ?
where i.companyname = c.companyname)
Don't know how your address.cityid maps to something so leave that one for you.
Related
I have 2 datasources. One Data Source provides details of employee (ID, Name etc) and their Departments. This is a Database. Another datasource is a manually maintained excel sheet in a sharedrive that has employee ID and a flag that states if the employee is a New Joiner Or Leaver. This dashboard however doesn't have Department information of employees.
I need a create an Dashboard, where the user can select a department and get details of employees that are flagged as Leavers in the excel datasource.
How can this be achieved?
I suggest you join your data in Tableau. First put your database table and then join excel to it. Use ID as a join key.
By joining you will have a dataset where flag is one column among others.
I am new to NoSql and DynamoDb, but from RDBMS..
My tables are being moved from MySql to DynamoDb. I have tables:
customer (columns: cid [PK], name, contact)
Hardware (columns: hid[PK], name, type )
Rent (columns: rid[PK], cid, hid, time) . => this is the association of customer and Hardware item.
one customer can have many Hardware Items and one Hardware Item can be shared among many customers.
Requirements: seperate lists of customers and hadware items should be able to retrieve.
Rent details- which customer barrowed which Hardeware Item.
I referred this - secondary index table. This is about keeping all columns in one table.
I thought to have 2 DynamoDb tables:
Customer - This has all attributes similar to columns AND set of hardware Item hash keys. (Then my issue is, when customer table is queried to retrieve only customers, all hardware keys are also loaded.)
Any guidance please for table structure? How to save, and load, and even updates ?
Any java samples please? (couldn't find any useful resource which similar to my scenario)
Have a look on DynamoDB's Adjacency List Design Pattern
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/bp-adjacency-graphs.html
In your case, based on Adjacency List Design Pattern, your schema can be designed as following
The prefix of partition key and sort key indicate the type of record.
If the record type is customer, both partition key and sort key should have the prefix 'customer-'.
If the record is that the customer rents the hardware, the partition key's prefix should be 'customer-' and the sort key's prefix should be 'hardware-'
base table
+------------+------------+-------------+
|PK |SK |Attributes |
|------------|------------|-------------|
|customer-cid|customer-cid|name, contact|
|hardware-hid|hardware-hid|name, type |
|customer-cid|hardware-hid|time |
+------------+------------+-------------+
Global Secondary Index Table
+------------+------------+----------+
|GSI-1-PK |GSI-1-SK |Attributes|
|------------|------------|----------|
|hardware-hid|customer-cid|time |
+------------+------------+----------+
customer and hardware should be stored in the same table. customer can refer to hardware by using
SELECT * FROM base_table WHERE PK=customer-123 AND SK.startsWith('hardware-')
if you hardware want to refer back to customer, you should use GSI table
SELECT * FROM GSI_table WHERE PK=hardware-333 AND SK.startsWith('customer-')
notice: the SQL I wrote is just pseudo code, to provide you an idea only.
Take a look at this answer, as it covers many of the basics which are relevant to you.
DynamoDB does not support foreign keys as such. Each table is independent and there are no special tools for keeping two tables synchronised.
You would probably have an attribute in your customers table called hardwares. The attribute would be a list of hardware ids the customer has. If you wanted to see all hardware items belonging to a customer you would:
Perform GetItem on the customer id. Or use Query depending on how you are looking the customer up.
For each hardware id in the customer's hardware attribute, perform a GetItem on the Hardware table.
With DynamoDB you generally end up doing more in the client application relative to an RDBMS solution. The benefits are that its fast and simple. But you will find you probably move a lot of your work from the database server to your client server.
I hope yo can point me in the right direction.
I have a SSRS report organized by Continent/Country/Customer and I need to change (force?) some of the customers to appear in a different region/country from the DB. ie:
I have a local NZ customer in the right Region/Country (australasia/New Zealand) but I want this one to show up in a different Region/Country namely (Asia/China) as this customer buys locally but exports all to China.
There are some others customers that needs to be manually organized, following the same criteria, of course.
any idea on how can I do this?
and will be the best option to do it through SQL-Server or SSRS?
Thanks in advance.
Eric
I would create a new table called something like AreaOverride with the following columns:
CustomerId
Continent
Country
Then link to this in your query using a left outer join and replace the Continent and Country with the overridden values if they exist:
Select CustomerId,
Case when AreaOverride.Continent is not null then AreaOverride.Continent else Customer.Continent end as Continent,
Case when AreaOverride.Country is not null then AreaOverride.Country else Customer.Country end as Country
From Customer
Left outer join AreaOverride On AreaOverride.CustomerId = Customer.CustomerId
You might want to make this a view if you are going to use it in several reports or other places.
Then whenever you need to override a customer's details you simply add a row for them in this table and the values will be overridden in your reports.
Note that if you are dealing with a vendor database rather than your own you don't want to be messing with their database structure but you can still do this by creating a new database and put the AreaOverride table in it. Then you add the database name to your join. For example if your database was called MyStuff then your join looks like this:
Left outer join MyStuff.dbo.AreaOveride On ...
I have a table with 2 different sets of customers form 2 different company, marked by an A or B in the company column. I am creating a report for invoices, i need to change the company name and details depending on it being company a or company b. Is this even possible. If not does anyone know of a good solution, or another option.?
Sounds like you need a table called tblCompany, with an Identifier column (A, B, etc...) and all other info like Name, Address, etc... Then you would make a query that joins your first table to tblCompany, on the Identifier column. Your report would be based off that query, where you could pull in the Name from tblCompany, and all the other info from the first table.
Unless there's something I'm not understanding?
I've got a CSV with some data that looks like this:
A0A0A0,48.5674500000,-54.8432250000,Gander,NL
A0A1A0,47.0073470000,-52.9589210000,Aquaforte,NL
A0A1B0,47.3622800000,-53.2939930000,Avondale,NL
But my database is normalized such that Cities and Provinces are in separate tables, each with their own ID column.
So what's the easiest way to import this file into 3 separate tables and link the foreign keys properly?
To be more clear, the tables are
cities (id, name, province_id)
provinces (id, code, name, country_id)
postal_codes (id, code, city_id)
countries (id, code, name)
Use COPY to import the csv into a temp table. Than use some INSERT INTO ... SELECT ... FROM ... to dump the data in the correct tables.
... my database is normalized
Doesn't appear to be. There are many issues, but the one that will trip you up in this question is, there does not seem to be correct PKs, no Unique Keys at all; so you will end up with duplicated data. Id "keys" do not prevent duplicate names, you need an unique index on name. It is not clear how you support two towns with the same name in the same province.
You know you have to load three tables from the one imported table. Due to FKs, which are a Good Thing, you need to load Provinces first, then Cities, then PostalCodes. But from the look of your import file, it is cities (or towns or localities or suburbs) ... that resolution needs to be clearly identified first. There are 360 kilometres and dozens of localities between Gander and Aquaforte. What exactly constitutes a record in the file ?
It may help to understand the structure on the excellent Canadian postal code system.
Then you need to check what level of granularity you are storing in the Db. Apparently Cities or towns, but not suburbs, not localities. What about Counties or Parishes ? Eg _0A ___ means it is a rural area; since you are storing cities, not counties, not municipalities, you can ignore them.
Once you are clear about the granularity or resolution of the source data, and the level of resolution you want in the target tables, you can then load the import file, most probably is several waves per table. The SQL is easy.