how to load multiple CSV files into Multiple Tables - sql

I have Multiple CSV files in Folder
Example :
Member.CSv
Leader.CSv
I need to load them in to Data base tables .
I have worked on it using ForEachLoop Container ,Data FlowTask, Excel Source and OLEDB Destination
we can do if by using Expressions and Precedence Constraints but how can I do using Script task if I have more than 10 files ..I got Stuck with this one

We have a similar issue, our solution is a mixture of the suggestions above.
We have a number of files types sent from our client on a daily basis.
These have a specific filename pattern (e.g. SalesTransaction20160218.csv, Product20160218.csv)
Each of these file types have a staging "landing" table of the structure you expect
We then have a .net script task that takes the filename pattern and loads that data into a landing table.
There are also various checks that are done within the csv parser - matching number of columns, some basic data validation, before loading into the landing table
We are not good enough .net programmers to be able to dynamically parse an unknown file structure, create SQL table and then load the data in. I expect it is feasible, after all, that is what the SSIS Import/Export Wizard does (with some manual intervention)
As an alternative to this (the process is quite delicate), we are experimenting with a HDFS data landing area, then it allows us to use analytic tools like R to parse the data within HDFS. After that utilising PIG to load the data into SQL.

Related

Trouble loading data into Snowflake using Azure Data Factory

I am trying to import a small table of data from Azure SQL into Snowflake using Azure Data Factory.
Normally I do not have any issues using this approach:
https://learn.microsoft.com/en-us/azure/data-factory/connector-snowflake?tabs=data-factory#staged-copy-to-snowflake
But now I have an issue, with a source table that looks like this:
There is two columns SLA_Processing_start_time and SLA_Processing_end_time that have the datatype TIME
Somehow, while writing the data to the staged area, the data is changed to something like 0:08:00:00.0000000,0:17:00:00.0000000 and that causes for an error like:
Time '0:08:00:00.0000000' is not recognized File
The mapping looks like this:
I have tried adding a TIME_FORMAT property like 'HH24:MI:SS.FF' but that did not help.
Any ideas to why 08:00:00 becomes 0:08:00:00.0000000 and how to avoid it?
Finally, I was able to recreate your case in my environment.
I have the same error, a leading zero appears ahead of time (0: 08:00:00.0000000).
I even grabbed the files it creates on BlobStorage and the zeros are already there.
This activity creates CSV text files without any error handling (double quotes, escape characters etc.).
And on the Snowflake side, it creates a temporary Stage and loads these files.
Unfortunately, it does not clean up after itself and leaves empty directories on BlobStorage. Additionally, you can't use ADLS Gen2. :(
This connector in ADF is not very good, I even had problems to use it for AWS environment, I had to set up a Snowflake account in Azure.
I've tried a few workarounds, and it seems you have two options:
Simple solution:
Change the data type on both sides to DateTime and then transform this attribute on the Snowflake side. If you cannot change the type on the source side, you can just use the "query" option and write SELECT using the CAST / CONVERT function.
Recommended solution:
Use the Copy data activity to insert your data on BlobStorage / ADLS (this activity did it anyway) preferably in the parquet file format and a self-designed structure (Best practices for using Azure Data Lake Storage).
Create a permanent Snowflake Stage for your BlobStorage / ADLS.
Add a Lookup activity and do the loading of data into a table from files there, you can use a regular query or write a stored procedure and call it.
Thanks to this, you will have more control over what is happening and you will build a DataLake solution for your organization.
My own solution is pretty close to the accepted answer, but I still believe that there is a bug in the build-in direct to Snowflake copy feature.
Since I could not figure out, how to control that intermediate blob file, that is created on a direct to Snowflake copy, I ended up writing a plain file into the blob storage, and reading it again, to load into Snowflake
So instead having it all in one step, I manually split it up in two actions
One action that takes the data from the AzureSQL and saves it as a plain text file on the blob storage
And then the second action, that reads the file, and loads it into Snowflake.
This works, and is supposed to be basically the same thing the direct copy to Snowflake does, hence the bug assumption.

Add filename as column on import to BigQuery?

This is a question about importing data files from Google Cloud Storage to BigQuery.
I have a number of JSON files that follow a strict naming convention to include some key data not included in the JSON data itself.
For example:
xxx_US_20170101.json.gz
xxx_GB_20170101.json.gz
xxx_DE_20170101.json.gz
Which is client_country_date.json.gz At the moment, I have some convoluted processes in a Ruby app that reads the files, appends the additional data and then writes it back to a file that is then imported into a single daily table for the client in BigQuery.
I am wondering if it is possible to grab and parse the filename as part of the import to BigQuery? I could then drop the convoluted Ruby processes which occasionally fail on larger files.
You could define an external table pointing to your files:
Note that the table type is "external table", and that it points to multiple files with the * glob.
Now you can query for all data in these files, and query for the meta-column _FILE_NAME:
#standardSQL
SELECT *, _FILE_NAME filename
FROM `project.dataset.table`
You can now save these results to a new native table.

SQL Server - Copying data between tables where the Servers cannot be connected

We want some of our customers to be able to export some data into a file and then we have a job that imports that into a blank copy of a database at our location. Note: a DBA would not be involved. This would be a function within our application.
We can ignore table schema differences - they will match. We have different tables to deal with.
So on the customer side the function would ran somethiug like:
insert into myspecialstoragetable select * from source_table
insert into myspecialstoragetable select * from source_table_2
insert into myspecialstoragetable select * from source_table_3
I then run a select * from myspecialstoragetable and get a .sql file they can then ship to me which we can then use some job/sql script to import into our copy of the db.
I'm thinking we can use XML somehow, but I'm a little lost.
Thanks
Have you looked at the bulk copy utility bcp? You can wrap it with your own program to make it easier for less sophisticated users.
Since it is a function within your application, in what language is the application front-end written ? If it is .NET, you can use Data Transformation Services in SQL Server to do a sample export. In the last step, you could save the steps into a VB/.NET module. If necessary, modify this file to change table names etc. Integrate this DTS module into your application. While doing the sample export, export it to a suitable format such as .CSV, .Excel etc, whichever format from which you will be able to import into a blank database.
Every time the user wants do an export, he will have to click on a button that would invoke the DTS module integrated into your application, that will dump the data to the desired format. He can mail such file to you.
If your application is not written in .NET, in whichever language it is written, it will have options to read data from SQL Server and dump them to a .CSV or text file with delimiters. If it is a primitive language, you may have to do it by concatenating the fields of every record, by looping through the records and writing to a file.
XML would be too far-fetched for this, though it's not impossible. At your end, you should have the ability to parse the XML file and import it into your location. Also, XML is not really suited if the no. of records are too large.
You probably think of a .sql file, as in MySql. In SQL Server, .sql files, that are generated by the 'Generate Scripts' function of SQL Server's interface, are used for table structures/DDL rather than the generation of the insert statements for each of the record's hard values.

Talend ETL tool

I am developing a migration tool and using Talend ETL tool (Free edition).
Challenges faced:-
is it possible to create a Talend job that uses dynamic schema every time it runs i.e. no hard-coded mappings in tMap component.
I want user to give a input CSV/Excel file and the job should create mappings on the basis of that input file. Is it possible in talend?
Any other free source ETL tool can also be helpful, or any sample job.
Yes, this can be done in Talend but if you do not wish to use a tMap then your table and file must match exactly. The way we have implemented it is for stage tables which are all datatype of varchar. This works when you are loading raw data into a stage table, and your validation is done after the load, prior to loading the stage data into a data warehouse.
Here is a summary of our method:
the filenames contain the table name so the process starts with a tFileList and parsing out the table name from the file name.
using tMSSQLColumnList obtain each column name, type, and length for the table (one way is to store it as an inline table in tFixedFlowInput)
run this thru a tSetDynamicSchema to produce your dynamic for that table
use a file input reference the dynamic schema.
load that into a MSSQLOutput again referencing the dynamic schema.
One more note on data types. It may work with data types than varchar, but our stage tables only have varchar and datetime. We had issues with datetime, so we filtered out those column types with a tMap.
Keep in mind, this is a summary to point you in the right direction, not a precise tutorial. But with this info in your hands, it can save you many hours of work while building your solution.

Bteq Scripts to copy data between two Teradata servers

How do I copy data from multiple tables within one database to another database residing on a different server?
Is this possible through a BTEQ Script in Teradata?
If so, provide a sample.
If not, are there other options to do this other than using a flat-file?
This is not possible using BTEQ since you have mentioned both the databases are residing in different servers.
There are two solutions for this.
Arcmain - You need to use Arcmain Backup first, which creates files containing data from your tables. Then you need to use Arcmain restore which restores the data from the files
TPT - Teradata Parallel Transporter. This is a very advanced tool. This does not create any files like Arcmain. It directly moves the data between two teradata servers.(Wikipedia)
If I am understanding your question, you want to move a set of tables from one DB to another.
You can use the following syntax in a BTEQ Script to copy the tables and data:
CREATE TABLE <NewDB>.<NewTable> AS <OldDB>.<OldTable> WITH DATA AND STATS;
Or just the table structures:
CREATE TABLE <NewDB>.<NewTable> AS <OldDB>.<OldTable> WITH NO DATA AND NO STATS;
If you get real savvy you can create a BTEQ script that dynamically builds the above statement in a SELECT statement, exports the results, then in turn runs the newly exported file all within a single BTEQ script.
There are a bunch of other options that you can do with CREATE TABLE <...> AS <...>;. You would be best served reviewing the Teradata Manuals for more details.
There are a few more options which will allow you to copy from one table to another.
Possibly the simplest way would be to write a smallish program which uses one of their communication layers (ODBC, .NET Data Provider, JDBC, cli, etc.) and use that to take a select statement and an insert statement. This would require some work, but it would have less overhead than trying to learn how to write TPT scripts. You would not need any 'DBA' permissions to write your own.
Teradata also sells other applications which hides the complexity of some of the tools. Teradata Data Mover handles provides an abstraction layer between tools like arcmain and tpt. Access to this tool is most likely restricted to DBA types.
If you want to move data from one server to another server then
We can do this with the flat file.
First we have fetch data from source table to flat file through any utility such as bteq or fastexport.
then we can load this data into target table with the help of mload,fastload or bteq scripts.