How can hive load data from csv? - apache

I want to implement apache hive and I want to load the data from csv file to hive table. So, here's the problem :
my csv file generated by SQL Server in it's structure have " sign, and it's become something like "04748/09","2248559","2248559","2009-12-03 00:00:00". So how can I only get the value without the " sign ?
Thanks a lot, I need your suggestions......


problem mention in your comment-how can I ignore the first line when import on hive like an mysql import?
From Hive v0.13.0, you can use skip.header.line.count. You could also specify the same while creating the table. For example:
Create external table testtable (name string, message string) row format delimited fields terminated by '\t' lines terminated by '\n' location '/testtable'
tblproperties ("skip.header.line.count"="1");
or
CREATE TABLE TEMP (f1 STRING, f2 String, f3 String, f4 String) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t' LINES TERMINATED BY '\n' TBLPROPERTIES("skip.header.line.count"="1");
load data local inpath 'test.csv'
overwrite into table TEMP;

Related

lines terminated by '\n' is not working when moving the data from hive view to a hive external table

I have given the external table creation in hive below
create external table tablename (column details)
row format delimited
fields terminated by ','
lines terminated by '\n'
location 'location in which the data gets stored'
However, after the creation and loading of that external table. I see that the underlying data file in the folder is containing the data in a single line. i.e the newline setting is not working.
I am running the hiveql through Azure hd insight cluster

AWS athena hive remove footer from csv file

While creating table in AWS Athena i have a problem with removing footer from imported csv file stored in AWS S3.
The query is pretty simple but im stuck on footer part.
CREATE EXTERNAL TABLE csvfile
(
col1 string
col2 string
col3 string
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY '|'
LINES TERMINATED BY '\n' STORED AS TEXTFILE
LOCATION
's3://xxxxx'
TBLPROPERTIES ("skip.header.line.count"='1',"skip.footer.line.count"='1');
The header is working perfectly fine but footer is not ;/ Any idea how to do it?
The problem is that "skip.footer.line.count"='1' is not removing the last row (summary in the csv file)

Hive External table-CSV File- Header row

Below is the hive table i have created:
CREATE EXTERNAL TABLE Activity (
column1 type, </br>
column2 type
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ','
LOCATION '/exttable/';
In my HDFS location /exttable, i have lot of CSV files and each CSV file also contain the header row. When i am doing select queries, the result contains the header row as well.
Is there any way in HIVE where we can ignore the header row or first line ?

you can now skip the header count in hive 0.13.0.
tblproperties ("skip.header.line.count"="1");

If you are using Hive version 0.13.0 or higher you can specify "skip.header.line.count"="1" in your table properties to remove the header.
For detailed information on the patch see: https://issues.apache.org/jira/browse/HIVE-5795

Lets say you want to load csv file like below located at /home/test/que.csv
1,TAP (PORTUGAL),AIRLINE
2,ANSA INTERNATIONAL,AUTO RENTAL
3,CARLTON HOTELS,HOTEL-MOTEL
Now, we need to create a location in HDFS that holds this data.
hadoop fs -put /home/test/que.csv /user/mcc
Next step is to create a table. There are two types of them to choose from. Refer this for choosing one.
Example for External Table.
create external table industry_
(
MCC string ,
MCC_Name string,
MCC_Group string
)
ROW FORMAT DELIMITED
FIELDS TERMINATED BY ','
STORED AS TEXTFILE
LOCATION '/user/mcc/'
tblproperties ("skip.header.line.count"="1");
Note: When accessed via Spark SQL, the header row of the CSV will be shown as a data row.
Tested on: spark version 2.4.

There is not. However, you can pre-process your files to skip the first row before loading into HDFS -
tail -n +2 withfirstrow.csv > withoutfirstrow.csv
Alternatively, you can build it into where clause in HIVE to ignore the first row.

If your hive version doesn't support tblproperties ("skip.header.line.count"="1"), you can use below unix command to ignore the first line (column header) and then put it in HDFS.
sed -n '2,$p' File_with_header.csv > File_with_No_header.csv

To remove the header from the csv file in place use:
sed -i 1d filename.csv

Importing CSV to MySQL with Load Data Infile

I'm trying to load a CSV file into MySQL, and I keep getting syntax errors:
load data infile 'c:/worldminwage.csv' fields terminated by ',' enclosed
by '"' lines terminated by '\n' (YearlyWage, PercentGDP, Date
effective);
Can anyone help me get this working? Thanks.

Valid syntax is LOAD DATA INFILE 'c:/worldminwage.csv' INTO TABLE tablename.
You forgot to mention which table the data should go in. See LOAD DATA INFILE Syntax

I think This would be more batter
LOAD DATA INFILE 'c:/worldminwage.csv' fields terminated by ',';
Because you will get rid of error like columns numbers are not matching in the .csv file and mysql table

MySQL creating and populating the database

I have downloaded the MySQL 5.2.5.1 version. I need to create the database and populate it. O have the data file in .csv format. I'm running the Mysql on windows. So when I create the database and a table in it, I want to populate the data from a file on my PC which is in .csv format.
I did it in this way:
load data local infile 'uniq.csv' into table tblUniq
fields terminated by ','
enclosed by '"'
lines terminated by '\n'
But it is not working for me. Where I am making a mistake?

You might need to change
lines terminated by '\n'
to
lines terminated by '\r\n'