R + Sql Server Script output to csv using R - sql

I am trying to run a process that rolls over several time periods using data that sits in a Sql Server 2008 R2 Database. If it were smaller I'd pull it all in to R and just subset based on date. However the data is ~15GB and I need to be able to generate csv files directly from Sql Server (I've found the R-Sql connectors to be too slow to move large amounts of data) via the R-SQL connector (RODBC, etc.) and then read them into R.
It seems that sqlcmd or bcp are the only options but I wanted to check before going in that direction.
Any suggestions would be appreciated.

I use the package RODBC a lot it works like a charm, large query using sqlQuery can take some times though. Once the query is done you will get a dataframe that you can easily export in csv via write.csv. It will work without any issues.

Related

Send data from CSV file to SQL Server automatically?

I have a table in SQL Server where I need to insert data on regular base. Each day I perform same task importing data manually, it makes me feel tedious so I need your help. Is it possible to send data from CSV file to SQL Server's existing table without doing manual procedure.
Or using python to create a scrip that send data from CSV file to SQL Server at fixed time automatically.
First you have to create a python script that inserts data into SQL server after reading CSV file. Then you should create a CRON job on your server that runs this script regularly. This might be a possible solution for your problem.

How to sync/update a database connection from MS Access to SQL Server

Problem:
I need to get data sets from CSV files into SQL Server Express (SSMS v17.6) as efficiently as possible. The data sets update daily into the same CSV files on my local hard drive. Currently using MS Access 2010 (v14.0) as a middleman to aggregate the CSV files into linked tables.
Using the solutions below, the data transfers perfectly into SQL Server and does exactly what I want. But I cannot figure out how to refresh/update/sync the data at the end of each day with the newly added CSV data without having to re-import the entire data set each time.
Solutions:
Upsizing Wizard in MS Access - This works best in transferring all the tables perfectly to SQL Server databases. I cannot figure out how to update the tables though without deleting and repeating the same steps each day. None of the solutions or links that I have tried have panned out.
SQL Server Import/Export Wizard - This works fine also in getting the data over to SSMS one time. But I also cannot figure out how to update/sync this data with the new tables. Another issue is that choosing Microsoft Access as the data source through this method requires a .mdb file. The latest MS Access file formats are .accdb files so I have to save the database in an older .mdb version in order to export it to SQL Server.
Constraints:
I have no loyalty towards MS Access. I really am just looking for the most efficient way to get these CSV files consistently into a format where I can perform SQL queries on them. From all I have read, MS Access seems like the best way to do that.
I also have limited coding knowledge so more advanced VBA/C++ solutions will probably go over my head.
TLDR:
Trying to get several different daily updating local CSV files into a program where I can run SQL queries on them without having to do a full delete and re-import each day. Currently using MS Access 2010 to SQL Server Express (SSMS v17.6) which fulfills my needs, but does not update daily with the new data without re-importing everything.
Thank you!
You can use a staging table strategy to solve this problem.
When it's time to perform the daily update, import all of the data into one or more staging tables. Execute SQL statement to insert rows that exist in the imported data but not in the base data into the base data; similarly, delete rows from the base data that don't exist in the imported data; similarly, update base data rows that have changed values in the imported data.
Use your data dependencies to determine in which order tables should be modified.
I would run all deletes first, then inserts, and finally all updates.
This should be a fun challenge!
EDIT
You said:
I need to get data sets from CSV files into SQL Server Express (SSMS
v17.6) as efficiently as possible.
The most efficient way to put data into SQL Server tables is using SQL Bulk Copy. This can be implemented from the command line, an SSIS job, or through ADO.Net via any .Net language.
You state:
But I cannot figure out how to refresh/update/sync the data at the end
of each day with the newly added CSV data without having to re-import
the entire data set each time.
It seems you have two choices:
Toss the old data and replace it with the new data
Modify the old data so that it comes into alignment with the new data
In order to do number 1 above, you'd simply replace all the existing data with the new data, which you've already said you don't want to do, or at least you don't think you can do this efficiently. In order to do number 2 above, you have to compare the old data with the new data. In order to compare two sets of data, both sets of data have to be accessible wherever the comparison is to take place. So, you could perform the comparison in SQL Server, but the new data will need to be loaded into the database for comparison purposes. You can then purge the staging table after the process completes.
In thinking further about your issue, it seems the underlying issue is:
I really am just looking for the most efficient way to get these CSV
files consistently into a format where I can perform SQL queries on
them.
There exist applications built specifically to allow you to query this type of data.
You may want to have a look at Log Parser Lizard or Splunk. These are great tools for querying and digging into data hidden inside flat data files.
An Append Query is able to incrementally add additional new records to an existing table. However the question is whether your starting point data set (CSV) is just new records or whether that data set includes records already in the table.
This is a classic dilemma that needs to be managed in the Append Query set up.
If the CSV includes prior records - then you have to establish the 'new records' data sub set inside the CSV and append just those. For instance if you have a sequencing field then you can use a > logic from the existing table max. If that is not there then one would need to do a NOT compare of the table data with the csv data to identify which csv records are not already in the table.
You state you seek something 'more efficient' - but in truth there is nothing more efficient than a wholesale delete of all records and write of all records. Most of the time one can't do that - but if you can I would just stick with it.

SQL, moving million records from a database to other database

I am a C# developer, I am not really good with SQL. I have a simple questions here. I need to move more than 50 millions records from a database to other database. I tried to use the import function in ms SQL, however it got stuck because the log was full (I got an error message The transaction log for database 'mydatabase' is full due to 'LOG_BACKUP'). The database recovery model was set to simple. My friend said that importing millions records using task->import data will cause the log to be massive and told me to use loop instead to transfer the data, does anyone know how and why? thanks in advance
If you are moving the entire database, use backup and restore, it will be the quickest and easiest.
http://technet.microsoft.com/en-us/library/ms187048.aspx
If you are just moving a single table read about and use the BCP command line tools for this many records:
The bcp utility bulk copies data between an instance of Microsoft SQL Server and a data file in a user-specified format. The bcp utility can be used to import large numbers of new rows into SQL Server tables or to export data out of tables into data files. Except when used with the queryout option, the utility requires no knowledge of Transact-SQL. To import data into a table, you must either use a format file created for that table or understand the structure of the table and the types of data that are valid for its columns.
http://technet.microsoft.com/en-us/library/ms162802.aspx
The fastest and probably most reliable way is to bulk copy the data out via SQL Server's bcp.exe utility. If the schema on the destination database is exactly identical to that on the source database, including nullability of columns, export it in "native format":
http://technet.microsoft.com/en-us/library/ms191232.aspx
http://technet.microsoft.com/en-us/library/ms189941.aspx
If the schema differs between source and target, you will encounter...interesting (yes, interesting is a good word for it) problems.
If the schemas differ or you need to perform any transforms on the data, consider using text format. Or another format (BCP lets you create and use a format file to specify the format of the data for export/import).
You might consider exporting data in chunks: if you encounter problems it gives you an easier time of restarting without losing all the work done so far.
You might also consider zipping the exported data files up to minimize time on the wire.
Then FTP the files over to the destination server.
bcp them in. You can use the bcp utility on the destination server for the BULK IMPORT statement in SQL Server to do the work. Makes no real difference.
The nice thing about using BCP to load the data is that the load is what is described as a 'non-logged' transaction, though it's really more like a 'minimally logged' transaction.
If the tables on the destination server have IDENTITY columns, you'll need to use SET IDENTITY statement to disable the identity column on the the table(s) involved for the nonce (don't forget to reenable it). After your data is imported, you'll need to run DBCC CHECKIDENT to get things back in synch.
And depending on what your doing, it can sometimes be helpful to put the database in single-user mode or dbo-only mode for the duration of the surgery: http://msdn.microsoft.com/en-us/library/bb522682.aspx
Another approach I've used to great effect is to use Perl's DBI/DBD modules (which provide access to the bulk copy interface) and write a perl script to suck out the data from the source server, transform it and bulk load it directly into the destination server, without having to save it to disk and move it. Also means you can trap errors and design things for recovery and restart right at the point of failure.
Use BCP to migrate data.
Another approach i have used in the past is to take a backup of the transaction log and shrink the log Prior to the migration. Split the migration script in parts and run the log backup- shrink - migrate iteration a few times.

How to Export data to Excel in SQL Server using SQL Jobs

I need to export the data from a particular table in my database to Excel files (.xls/.xlsx) that will be located into a shared folder into my network. Now the situation is like this -
I need to use SQL SERVER Agent Jobs.
2.I need to generate a new excel file in every 2 minutes that will contain the refreshed data.
I am using sql server 2008 that doesn't include BI development studio. I'm clueless how to solve this situation. First, I'm not sure how to export the data using jobs because every possible ways I tried had some issues with the OLEDB connection. The 'sp_makewebtask' is also not available in SQL 2008. And I'm also confused how to dynamically generate the names of the files.
Any reference or solution will be helpful.
Follow the steps given below :
1) Make a stored procedure that creates a temporary table and insert records to it.
2) Make a stored procedure that read records from that temporary table and writes to file. You can use this link : clickhere
3) Create an SQL-job that execute step 1 and step 2 sequentially.
I found a better way out. I have created a SSIS(SQL Server Integration Services) package to automate the whole Export to Excel task. Then I deployed that package using SQL Server Agent Jobs. This is a more neat and clean solution as I found.

Transfer data from local server to online server

I am using SQL Server 2008 R2 on my local PC. In my database there is one table with approx 98000 rows. Now I want to transfer that data directly to online server database. I have tried by making script of that table but when I run that script, it gives me error of insufficient memory. plz help me.. how can I do this. Thanks
There are a variety of strategies you can employ in this instance. Here's a few off the top of my head...
Got some .NET programming up your sleeve? Try the SqlBulkCopy class
Export the data to a transferable format, e.g. CSV file and then use BULK INSERT to insert the data.
Try using OPENROWSET to copy from the local to remote. Stackoverflow example
If you've got the full leverage of SSIS, example of SSIS is just here
A bit Heath Robinson but why not grab the data out into CSV and using some Excel skills, build the individual statements yourself. Example here using INSERT INTO and UNION
HTH