I am trying to import a large HDFS file into a mysql db. The data in the file is delimiter by a '^A'. How do I tell mysql to separate each column by ctrl-A? Also, is it possible for me to specify what fields I want to import.
See the documentation here:
http://dev.mysql.com/doc/refman/5.5/en/mysqlimport.html
You are looking for the --fields-terminated-by=string option. There is not option to only select certain fields for import, though you can use --columns=column_list to map columns in your data to fields in the table.
Related
I have to load several CSVs into some tables with Mysql LOAD DATA IN FILE, and I want to save discard records that could not be loaded (Because failed FKs, duplicates, etc.) in a discard file, such as Oracle SQL loader does
Any suggestion?
Thanks!
You can import data easily using MySQL WorkBench using import wizard through CSV. It has the option to import all the data and create new table. From there you can alter the tables later on or make necessary indexes as needed, or change dataTypes on the go.
Another option is to use LOAD DATA commands as usual. Import data to a newly created tables without the foreign keys. You can target csv columns to specific table columns as well. see https://dev.mysql.com/doc/refman/8.0/en/load-data.html
I have a CSV file with 9 columns but when I import it via MySQL Workbench it appears two extra columns with no values. A kind of solution is to deselect them but I want an explanation and a permanent solution to avoid this. Why is this happening? I attach a screenshot to see exactly what I say.
Sometimes in excel file type something and delete, excel file include or read blank columns or row.
If you delete those two columns after gameid in CSV file, after that import CSV file in mysql.
I have tables that are on different mysql instances. I want to export some data as csv from a mysql instance, and perform a left join on a table with the exported csv data. How can I achieve this?
Quite surprisingly that is possible with MySQL, there are several steps that you need to go through.
First create a template table using CSV engine and desired table layout. This is the table into which you will import your CSV file. Use CREATE TABLE yourcsvtable (field1 INT NOT NULL, field2 INT NOT NULL) ENGINE=CSV for example. Please note that NULL values are not supported by CSV engine.
Perform you SELECT to extract the CSV file. E.g. SELECT * FROM anothertable INTO OUTFILE 'temp.csv' FIELDS TERMINATED BY ',';
Copy temp.csv into your target MySQL data directory as yourcsvtable.CSV. Location and exact name of this file depends on your MySQL setup. You cannot perform the SELECT in step 2 directly into this file as it is already open - you need to handle this in your script.
Use FLUSH TABLE yourcsvtable; to reload/import the CSV table.
Now you can execute your query against the CSV file as expected.
Depending on your data you need to ensure that the data is correctly enclosed by quotation marks or escaped - this needs to be taken into account in step 2.
CSV file can be created by MySQL on some another server or by some other application as long as it is well-formed.
If you export it as CSV, it's no longer SQL, it's just plain row data. Suggest you export as SQL, and import into the second database.
I have 100+ XLSX files that I need to get into a MySQL Database. Each file is a bit different, so I've created a massive table that contains a field for each possible column header across all files. This way they can auto-map on import.
Using Navicat I can import the files one at a time, but I'm wondering if there is a way to import all of the files at one time?
I'm thinking 'no' but if your going to do this a lot I think there are ways to automate this.
Export your xls-files into csv-files instead. Write some script to transform them between csv-excel style to csv-mysql style.
Create tables for importing with the csv engine. Put your files inplace of the ones created by mysql and flush tables. Now your data is ready to be read inside mysql and copied over to more powerful tables engines.
Another way is to do a VBA-script that exports the data in a format recognized by load data infile and then load them using mysql.
As the title says: I've got a bunch of tab-separated text files containing data.
I know that if I use 'CREATE TABLE' statements to set up all the tables manually, I can then import them into the waiting tables, using 'load data' or 'mysqlimport'.
But is there any way in MySQL to create tables automatically based on the tab files? Seems like there ought to be. (I know that MySQL might have to guess the data type of each column, but you could specify that in the first row of the tab files.)
No, there isn't. You need to CREATE a TABLE first in any case.
Automatically creating tables and guessing field types is not part of the DBMS's job. That is a task best left to an external tool or application (That then creates the necessary CREATE statements).
If your willing to type the data types in the first row, why not type a proper CREATE TABLE statement.
Then you can export the excel data as a txt file and use
LOAD DATA INFILE 'path/file.txt' INTO TABLE your_table;