I'm trying to use oracle external tables to load flat files into a database but I'm having a bit of an issue with the location clause. The files we receive are appended with several pieces of information including the date so I was hoping to use wildcards in the location clause but it doesn't look like I'm able to.
I think I'm right in assuming I'm unable to use wildcards, does anyone have a suggestion on how I can accomplish this without writing large amounts of code per external table?
Current thoughts:
The only way I can think of doing it at the moment is to have a shell watcher script and parameter table. User can specify: input directory, file mask, external table etc. Then when a file is found in the directory, the shell script generates a list of files found with the file mask. For each file found issue a alter table command to change the location on the given external table to that file and launch the rest of the pl/sql associated with that file. This can be repeated for each file found with the file mask. I guess the benefit to this is I could also add the date to the end of the log and bad files after each run.
I'll post the solution I went with in the end which appears to be the only way.
I have a file watcher than looks for files in a given input dir with a certain file mask. The lookup table also includes the name of the external table. I then simply issue an alter table on the external table with the list of new file names.
For me this wasn't much of an issue as I'm already using shell for most of the file watching and file manipulation. Hopefully this saves someone searching for ages for a solution.
Related
Start situation:
a folder with lots of files (images mostly png).
two tables in database (MariaDB) which contains supposed image filenames. I query the filenames like this:
select filename from table1
UNION
select filename from table2;
I want to know if I have files not registered in the database tables.
My first approach is to put the list of filenames inside a textfile (I've used Linux command line, list is filename per line), but I don't know how to continue.
I can't write in the database. UPDATED. I got more auth to perform my job tasks. Therefore I solved this with the suggestion.
You need to do couple of things:
Import the file with list of files into the database.
Use cursor to go through the list of file names and match it to your table list which contains the list-b of file names
To import file name you can use the import method or directly read the file as a table virtually.
Thanks
I want to read a tab delimited file using PLSQL and insert the file data into a table.
Everyday new file will be generated.
I am not sure if external table will help here because filename will be changed based on date.
Filename: SPRReadResponse_YYYYMMDD.txt
Below is the sample file data.
Option that works on your own PC is to use SQL*Loader. As file name changes every day, you'd use your operating system's batch script (on MS Windows, these are .BAT files) to pass a different name while calling sqlldr (and the control file).
External table requires you to have access to the database server and have (at least) read privilege on its directory which contains those .TXT files. Unless you're a DBA, you'll have to talk to them to provide environment. As of changing file name, you could use alter table ... location which is rather inconvenient.
If you want to have control over it, use UTL_FILE; yes, you still need to have access to that directory on the database server, but - writing a PL/SQL script, you can modify whatever you want, including file name.
Or, a simpler option, first rename input file to SPRReadResponse.txt, then load it and save yourself of all that trouble.
I Googled for a solution to create a table, using Databticks and Azure SQL Server, and load data into this same table. I found some sample code online, which seems pretty straightforward, but apparently there is an issue somewhere. Here is my code.
CREATE TABLE MyTable
USING org.apache.spark.sql.jdbc
OPTIONS (
url "jdbc:sqlserver://server_name_here.database.windows.net:1433;database = db_name_here",
user "u_name",
password "p_wd",
dbtable "MyTable"
);
Now, here is my error.
Error in SQL statement: SQLServerException: Invalid object name 'MyTable'.
My password, unfortunately, has spaces in it. That could be the problem, perhaps, but I don't think so.
Basically, I would like to get this to recursively loop through files in a folder and sub-folders, and load data from files with a string pattern, like 'ABC*', and load recursively all these files into a table. The blocker, here, is that I need the file name loaded into a field as well. So, I want to load data from MANY files, into 4 fields of actual data, and 1 field that captures the file name. The only way I can distinguish the different data sets is with the file name. Is this possible? Or, is this an exercise in futility?
my suggestion is to use the Azure SQL Spark library, as also mentioned in documentation:
https://docs.databricks.com/spark/latest/data-sources/sql-databases-azure.html#connect-to-spark-using-this-library
The 'Bulk Copy' is what you want to use to have good performances. Just load your file into a DataFrame and bulk copy it to Azure SQL
https://docs.databricks.com/data/data-sources/sql-databases-azure.html#bulk-copy-to-azure-sql-database-or-sql-server
To read files from subfolders, answer is here:
How to import multiple csv files in a single load?
I finally, finally, finally got this working.
val myDFCsv = spark.read.format("csv")
.option("sep","|")
.option("inferSchema","true")
.option("header","false")
.load("mnt/rawdata/2019/01/01/client/ABC*.gz")
myDFCsv.show()
myDFCsv.count()
Thanks for a point in the right direction mauridb!!
I have a directory containing multiple xlsx files and what I want to do is to insert the data from the files in to a database.
So far I have solved this by using tFileList -> tFileInputExcel -> tPostgresOutput
My problem begins when one of this files doesn't match the defined schema and returns an error resulting on a interruption of a workflow.
What I need to figure out is if it's possible skip that file (moving it to another folder for instance) and continuing iterating the rest of existing files.
If I check the option "Die on error" the process ends and doesn't process the rest of the files.
I would approach this by making your initial input schema on the tFileInputExcel be all strings.
After reading the file I would then validate the schema using a tSchemaComplianceCheck set to "Use another schema for compliance check".
You should be able to then connect a reject link from the tSchemaComplianceCheck to a tFileCopy configured to move the file to a new directory (if you want it to move it then just tick "Remove source file").
Here's a quick example:
With the following set as the other schema for the compliance check (notice how it now checks that id and age are Integers):
And then to move the file:
Your main flow from the tSchemaComplianceCheck can carry on using just strings if you are inserting into a database. You might want to use a tConvertType to change things back to the correct data types after this if you are doing any processing that requires proper data types or you are using your tPostgresOutput component to create the table as well.
I'm attempting to pull data from several spreadsheets that reside in a single folder, then put all the data into a single csv file along with column headings.
I have a foreach loop container setup to iterate through each of the filenames in the folder, which then appends this data to a RAW file, however as many have seemed to run into, there does not appear to be a built in option that will allow one to simply truncate the RAW file before entering the loop container.
Jamie Thompson described a similar situation in his blog here, but the links to the examples do not seem to work. Does anyone have an easy way to truncate the RAW file in a stand alone step before entering the foreach loop?
The approach I always use is to create a data flow with the appropriate metadata format but no actual rows and route that to a RAW file set to Create new.
In my existing data flow, I look at the metadata that populates the RAW file and then craft a select statement that mimics it.
e.g.
SELECT
CAST(NULL AS varchar(70)) AS AddressLine1
, CAST(NULL AS bigint) AS SomeBigInt
, CAST(NULL AS nvarchar(max)) AS PerformanceLOL
Here's what I would did:
Make your initial raw file
Make a copy of that raw file
Use a file task to replace the staging file at the beginning of your package/job every time.
In my use case I have 20 foreach threads writing to their own files all at the same time. No thread can create and then append, so you just "recreate" by copying over an 'empty' raw file that already has the meta data assigned, before calling the threads: