hiveql

问题 For my requirement i have to implement upper and lower limit in hive. For that i am trying to write query something like this SELECT * FROM `your_table` LIMIT 0, 5 SELECT * FROM `your_table` LIMIT 5, 5 But hive supports only 1 limit, it's not supporting upper and lower limit. I tried with with other alternatives to achieve this by using RANK(), ROWNUM() but didn't succeeded. Can anyone please help me to solve this. Thanks in advance. 回答1: Hi you can use the Facebook UDF and rownum

问题 I'm trying to match phone numbers to an area using Hive. I've got a table (prefmap) that maps a number prefix (prefix) to an area (area) and another table (users) with a list of phone numbers (nb). There is only 1 match per phone number (no sub-area) The problem is that the length of the prefixes is not fixed so I cannot use the UDF function substr(nb,"prefix's length") in the JOIN's ON() condition to match the substring of a number to a prefix. And when I try to use instr() to find if a

问题 I am running queries in a hive environment. I have a column which has a timestamp but is set up a string in the tables. I tried the following : all of them return Null SELECT ,To_date(activitydate) Cast: ,cast(activitydate as timestamp) This is the how the data is set up in the table: Appreciate any inputs on how I can convert this : 05/12/2017 00:00:00 SELECT cust_id ,to_date(activitydate) activity_date ,type type_of_contact FROM repl_task WHERE to_date(activitydate) BETWEEN '2014-01-01' AND

问题 I was trying to parameterise the value in hive rather than hard coding it in query. Below is the query. select * from employee where sal >30000 But rather than using 30000 value as hard coded I need that to come from the same query like below. But I am running into issues : select * from employee where sal > (select max(sal) from employee) Any help is appreciated. Thanks 回答1: You can try using this form of Hive query. This will get the employees having salary equal to the highest salary.

问题 I have a main table (Employee) which is having 10 columns and I can load data into it using load data inpath /file1.txt into table Employee My question is how to handle the same table (Employee) if my file file2.txt has same columns but column 3 and columns 5 are missing. if I directly load data last columns will be NULL NULL . but instead it should load 3rd as NULL and 5th column as NULL. Suppose I have a table Employee and I want to load the file1.txt and file2.txt to table. file1.txt =====

问题 I have below table in hive with column id, name and time stamp: On the basis of time stamp below should be the output as latest record: 回答1: You don't need rank for this. Your output is described by: select t.* from t order by t.transaction_time desc limit 3; EDIT: Oh, you want rank() or dense_rank() : select t.* from (select t.*, dense_rank() over (order by t.transaction_time desc) as seqnum from t ) t where seqnum = 1; 回答2: You can use either rank or row_number for this: select * from (

问题 How can I convert a string to an array of characters, for example "abcd" -> ["a","b","c","d"] I know the split methd: SELECT split("abcd",""); #["a","b","c","d",""] is a bug for the last whitespace? or any other ideas? 回答1: This is not actually a bug. Hive split function simply calls the underlying Java String#split(String regexp, int limit) method with limit parameter set to -1 , which causes trailing whitespace(s) to be returned. I'm not going to dig into implementation details on why it's

问题 When attempting to run an HQL script with the following logic, I receive the error: ParseException line 4:0 cannot recognize input near 'CASE' 'WHEN' 'mytable' in serde properties specification Script Logic INSERT OVERWRITE DIRECTORY '/example/path' ROW FORMAT DELIMITED FIELDS TERMINATED BY ',' CASE WHEN ${hiveconf:tbl_name}='mytable' THEN SELECT * FROM ${hiveconf:tbl_name} LEFT OUTER JOIN ...; WHEN ${hiveconf:tbl_name}='mytable2' THEN SELECT * FROM ${hiveconf:tbl_name} LEFT OUTER JOIN ...;

问题 The following discussion seems to indicate that Hive timestamps have a timezone: https://community.hortonworks.com/questions/83523/timestamp-in-hive-without-timezone.html The apache wiki says "Timestamps are interpreted to be timezoneless and stored as an offset from the UNIX epoch." I am referring to: https://cwiki.apache.org/confluence/display/Hive/LanguageManual+Types#LanguageManualTypes-TimestampstimestampTimestamps If I use code like the following: from_unixtime(unix_timestamp(ts_field,

问题 How to compare two tables with same structures in hive. I believe minus will not work in hive. SRC table: id name 1 A 2 B 3 C TGT table: id name 1 A 2 C 3 C can anyone help me with a query. 回答1: If you are looking for equality between two tables and for differences if any, you can do like following SELECT MIN(TableName) as TableName, ID, NAME FROM ( SELECT 'SRC_TABLE' as TableName, A.ID, A.NAME FROM A UNION ALL SELECT 'TGT_TABLE' as TableName, B.ID, B.NAME FROM B ) tmp GROUP BY ID, NAME