Hive select distinct one column

Jun 24, 2015 · Returns the sum of the elements in the group or sum of the distinct values of the column in the group. MySQL hive> select sum(sal) from Tri100; OK 150000 Time taken: 17.909 seconds, Fetched: 1 row(s) hive> select Sum(sal) from Tri100 where loccation='Banglore'; OK 55000 Time taken: 18.324 seconds, Fetched: 1 row(s) Mar 02, 2012 · try this query,i m assuming u hve one more table TABLE_C WITH SAME STRUCTURE AS table_b, INSERT INTO TABLE_C SELECT distinct b.* FROM TABLE_B b ,TABLE_A a WHERE b.IMEI NOT IN (SELECT a.IMEI FROM TABLE_A a) OR (b.IMEI=a.IMEI AND (b.LATITUDE<>a.LATITUDE OR b.LONGITUDE<>a.LONGITUDE)) hope this helps.. revert back with ur comments... Dec 24, 2019 · println("Distinct Count: " + df.distinct().count()) This yields output “Distinct Count: 8” Using SQL Count Distinct. distinct() runs distinct on all columns, if you want to get count distinct on selected columns, use the Spark SQL function countDistinct(). This function returns the number of distinct elements in a group. this is problematic, since I need to receive both X and Y but with X distinct. In some DBs this can be done using "select distinct on x,y from tabel" but hive dosent support "distinct on" – Tomer Sep 25 '11 at 8:37 Sep 16, 2015 · We can count during aggregation using GROUP BY to make distinct when needed after the select statement to show the data with counts. Remember that you must include the columns that are before the count in GROUP BY: SELECT &lt;column&gt;, COUNT(&lt;column&gt;)... Teams. Q&A for Work. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Learn more this is problematic, since I need to receive both X and Y but with X distinct. In some DBs this can be done using "select distinct on x,y from tabel" but hive dosent support "distinct on" – Tomer Sep 25 '11 at 8:37 I have a hive table that looks like this (total 460 columns) colA colB ..... ce_id filename ..... dt v j 4 gg 40 v j 5 gg ... Dec 24, 2019 · println("Distinct Count: " + df.distinct().count()) This yields output “Distinct Count: 8” Using SQL Count Distinct. distinct() runs distinct on all columns, if you want to get count distinct on selected columns, use the Spark SQL function countDistinct(). This function returns the number of distinct elements in a group. Assume the name of hive table is “transact_tbl” and it has one column named as “connections”, and values in connections column are comma separated and total two commas are present in each value. Step 1: Create Hive Table. Create an input table transact_tbl in bdp schema using below command. SELECT whatever FROM more.data AS a JOIN (SELECT DISTINCT(column) AS col1 FROM some.table) AS b ON a.col1 = b.col1 /* additional joins, clauses etc... I normally test to see which is faster and go with that one. Dec 24, 2019 · println("Distinct Count: " + df.distinct().count()) This yields output “Distinct Count: 8” Using SQL Count Distinct. distinct() runs distinct on all columns, if you want to get count distinct on selected columns, use the Spark SQL function countDistinct(). This function returns the number of distinct elements in a group. select hash, line, p1, p2, p3 from stage_new. UNION DISTINCT. select hash, line, mb.p1, mb.p2, mb.p3 from master_base mb JOIN new_parts np ON (mb.p1 = np.p1 AND mb.p2 = np.p2 AND mb.p3 = np.p3); ##master_base BEFORE Insert of dedupe required data## hive> select * from master_base; OK. 12 THEDUPE 1 1 1. 11 test2 1 1 2. 10 test3 2 1 1. 9 test4 2 1 1 Feb 27, 2019 · Note, Hive supports SELECT DISTINCT * starting in release 1.1.0 (HIVE-9194). hive> SELECT col1, col2 FROM t1 1 3 1 3 1 4 2 5 hive> SELECT DISTINCT col1, col2 FROM t1 1 3 1 4 2 5 hive> SELECT DISTINCT col1 FROM t1 1 2 ALL and DISTINCT can also be used in a UNION clause – see Union Syntax for more information. Feb 27, 2019 · Note, Hive supports SELECT DISTINCT * starting in release 1.1.0 (HIVE-9194). hive> SELECT col1, col2 FROM t1 1 3 1 3 1 4 2 5 hive> SELECT DISTINCT col1, col2 FROM t1 1 3 1 4 2 5 hive> SELECT DISTINCT col1 FROM t1 1 2 ALL and DISTINCT can also be used in a UNION clause – see Union Syntax for more information. Feb 26, 2020 · COUNT() function and SELECT with DISTINCT on multiple columns. You can use the count() function in a select statement with distinct on multiple columns to count the distinct rows. Here is an example: SELECT COUNT(*) FROM ( SELECT DISTINCT agent_code, ord_amount,cust_code FROM orders WHERE agent_code='A002'); Output: SELECT DISTINCT c_birth_country FROM customer; -- Returns the unique combinations of values from multiple columns. SELECT DISTINCT c_salutation, c_last_name FROM customer; You can use DISTINCT in combination with an aggregation function, typically COUNT(), to find how many different values a column contains.-- Counts the unique values from one ... The notation COUNT(column_name) only considers rows where the column contains a non-NULL value. You can also combine COUNT with the DISTINCT operator to eliminate duplicates before counting, and to count the combinations of values across multiple columns. When the query contains a GROUP BY clause, returns one value for each combination of ... Unfortunately, according to the Hive Language Manual, Hive's DISTINCT expression works on entire tables so doing something like this is not an option: SELECT DISTINCT(ID, SubCategory), DateTime, Category FROM sometable The notation COUNT(column_name) only considers rows where the column contains a non-NULL value. You can also combine COUNT with the DISTINCT operator to eliminate duplicates before counting, and to count the combinations of values across multiple columns. When the query contains a GROUP BY clause, returns one value for each combination of ... SELECT whatever FROM more.data AS a JOIN (SELECT DISTINCT(column) AS col1 FROM some.table) AS b ON a.col1 = b.col1 /* additional joins, clauses etc... I normally test to see which is faster and go with that one. Sep 25, 2020 · select isnotnull( NULL ); Hive CASE conditional function examples. select case x when 1 then 'one' when 2 then 'two' when 0 then 'zero' else 'out of range' end from t1; select case when dayname(now()) in ('Saturday','Sunday') then 'result undefined on weekends' when x > y then 'x greater than y' when x = y then 'x and y are equal' when x is null or y is null then 'one of the columns is null ... Nov 28, 2017 · Distinct support in Hive 2.1.0 and later (see HIVE-9534) Distinct is supported for aggregation functions including SUM, COUNT and AVG, which aggregate over the distinct values within each partition. Current implementation has the limitation that no ORDER BY or window specification can be supported in the partitioning clause for performance reason. Mar 02, 2012 · try this query,i m assuming u hve one more table TABLE_C WITH SAME STRUCTURE AS table_b, INSERT INTO TABLE_C SELECT distinct b.* FROM TABLE_B b ,TABLE_A a WHERE b.IMEI NOT IN (SELECT a.IMEI FROM TABLE_A a) OR (b.IMEI=a.IMEI AND (b.LATITUDE<>a.LATITUDE OR b.LONGITUDE<>a.LONGITUDE)) hope this helps.. revert back with ur comments... Dec 24, 2019 · println("Distinct Count: " + df.distinct().count()) This yields output “Distinct Count: 8” Using SQL Count Distinct. distinct() runs distinct on all columns, if you want to get count distinct on selected columns, use the Spark SQL function countDistinct(). This function returns the number of distinct elements in a group. Hive column name. HIVE_COLUMN_TYPE. VARCHAR2(4000) Data type of the Hive column. ORACLE_COLUMN_TYPE. VARCHAR2(4000) Equivalent Oracle data type of the Hive column. LOCATION. VARCHAR2(4000) Physical location of the Hive table. OWNER. VARCHAR2(4000) Owner of the Hive table. CREATION_TIME. DATE. Time that the Hive column was created. HIVE_URI ... select DISTINCT in HIVE DISTINCT keyword is used in SELECT statement in HIVE to fetch only unique rows. The row does not mean entire row in the table but it means “row” as per column listed in the SELECT statement. If the SELECT has 3 columns listed then SELECT DISTINCT will fetch unique row for those 3 column values only. Feb 26, 2020 · COUNT() function and SELECT with DISTINCT on multiple columns. You can use the count() function in a select statement with distinct on multiple columns to count the distinct rows. Here is an example: SELECT COUNT(*) FROM ( SELECT DISTINCT agent_code, ord_amount,cust_code FROM orders WHERE agent_code='A002'); Output: <Select Clause> <rferenced Columns> from <table_name> Group By <The columns on which we want to group the data> Select department, count(*) from the university.college Group By department; Here the department refers to one of the columns of the college table which is present in the university database and its value is various in departments ... Feb 27, 2019 · Note, Hive supports SELECT DISTINCT * starting in release 1.1.0 (HIVE-9194). hive> SELECT col1, col2 FROM t1 1 3 1 3 1 4 2 5 hive> SELECT DISTINCT col1, col2 FROM t1 1 3 1 4 2 5 hive> SELECT DISTINCT col1 FROM t1 1 2 ALL and DISTINCT can also be used in a UNION clause – see Union Syntax for more information. The Spark distinct () function is by default applied on all the columns of the dataframe. If you need to apply on specific columns then first you need to select them. Lets check an example. Create a dataframe with Name, Age and, Height column. — Returns the unique values from one column. — NULL is included in the set of values if any rows have a NULL in this column. select distinct c_birth_country from Employees; — Returns the unique combinations of values from multiple columns. select distinct c_salutation, c_last_name from Employees; this is problematic, since I need to receive both X and Y but with X distinct. In some DBs this can be done using "select distinct on x,y from tabel" but hive dosent support "distinct on" – Tomer Sep 25 '11 at 8:37 Feb 27, 2019 · Note, Hive supports SELECT DISTINCT * starting in release 1.1.0 (HIVE-9194). hive> SELECT col1, col2 FROM t1 1 3 1 3 1 4 2 5 hive> SELECT DISTINCT col1, col2 FROM t1 1 3 1 4 2 5 hive> SELECT DISTINCT col1 FROM t1 1 2 ALL and DISTINCT can also be used in a UNION clause – see Union Syntax for more information. Hive supports subqueries only in the FROM clause (through Hive 0.12). The subquery has to be given a name because every table in a FROM clause must have a name. Columns in the subquery select list must have unique names. The columns in the subquery select list are available in the outer query just like columns of a table.

Nov 28, 2017 · Distinct support in Hive 2.1.0 and later (see HIVE-9534) Distinct is supported for aggregation functions including SUM, COUNT and AVG, which aggregate over the distinct values within each partition. Current implementation has the limitation that no ORDER BY or window specification can be supported in the partitioning clause for performance reason. The DISTINCT clause can be used only in the SELECT statement. Note that DISTINCT is synonym of UNIQUE which is not SQL standard. It is a good practice to always use DISTINCT instead of UNIQUE. Oracle SELECT DISTINCT examples. Let’s look at some examples of using SELECT DISTINCT to see how it works. A) Oracle SELECT DISTINCT one column example select hash, line, p1, p2, p3 from stage_new. UNION DISTINCT. select hash, line, mb.p1, mb.p2, mb.p3 from master_base mb JOIN new_parts np ON (mb.p1 = np.p1 AND mb.p2 = np.p2 AND mb.p3 = np.p3); ##master_base BEFORE Insert of dedupe required data## hive> select * from master_base; OK. 12 THEDUPE 1 1 1. 11 test2 1 1 2. 10 test3 2 1 1. 9 test4 2 1 1 Assume the name of hive table is “transact_tbl” and it has one column named as “connections”, and values in connections column are comma separated and total two commas are present in each value. Step 1: Create Hive Table. Create an input table transact_tbl in bdp schema using below command. Teams. Q&A for Work. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Learn more The Spark distinct () function is by default applied on all the columns of the dataframe. If you need to apply on specific columns then first you need to select them. Lets check an example. Create a dataframe with Name, Age and, Height column. Hive column name. HIVE_COLUMN_TYPE. VARCHAR2(4000) Data type of the Hive column. ORACLE_COLUMN_TYPE. VARCHAR2(4000) Equivalent Oracle data type of the Hive column. LOCATION. VARCHAR2(4000) Physical location of the Hive table. OWNER. VARCHAR2(4000) Owner of the Hive table. CREATION_TIME. DATE. Time that the Hive column was created. HIVE_URI ... The notation COUNT(column_name) only considers rows where the column contains a non-NULL value. You can also combine COUNT with the DISTINCT operator to eliminate duplicates before counting, and to count the combinations of values across multiple columns. When the query contains a GROUP BY clause, returns one value for each combination of ... I have a hive table that looks like this (total 460 columns) colA colB ..... ce_id filename ..... dt v j 4 gg 40 v j 5 gg ... Unfortunately, according to the Hive Language Manual, Hive's DISTINCT expression works on entire tables so doing something like this is not an option: SELECT DISTINCT(ID, SubCategory), DateTime, Category FROM sometable Sep 16, 2015 · We can count during aggregation using GROUP BY to make distinct when needed after the select statement to show the data with counts. Remember that you must include the columns that are before the count in GROUP BY: SELECT &lt;column&gt;, COUNT(&lt;column&gt;)... Dec 24, 2019 · println("Distinct Count: " + df.distinct().count()) This yields output “Distinct Count: 8” Using SQL Count Distinct. distinct() runs distinct on all columns, if you want to get count distinct on selected columns, use the Spark SQL function countDistinct(). This function returns the number of distinct elements in a group. Feb 10, 2017 · For example, the following is possible because count (DISTINCT) and sum (DISTINCT) specify the same column: INSERT OVERWRITE TABLE pv_gender_agg SELECT pv_users.gender, count (DISTINCT pv_users.userid), count (*), sum (DISTINCT pv_users.userid) FROM pv_users GROUP BY pv_users.gender; Answered November 18, 2016 · Author has 88 answers and 256K answer views. In HIVE, I tried getting the count of distinct rows in 2 methods, SELECT COUNT (*) FROM (SELECT DISTINCT columns FROM table); SELECT COUNT (DISTINCT columns) FROM table; Both are yielding DIFFERENT RESULTS. The count for the first query is greater than the second query. — Returns the unique values from one column. — NULL is included in the set of values if any rows have a NULL in this column. select distinct c_birth_country from Employees; — Returns the unique combinations of values from multiple columns. select distinct c_salutation, c_last_name from Employees; The notation COUNT(column_name) only considers rows where the column contains a non-NULL value. You can also combine COUNT with the DISTINCT operator to eliminate duplicates before counting, and to count the combinations of values across multiple columns. When the query contains a GROUP BY clause, returns one value for each combination of ... Feb 26, 2020 · COUNT() function and SELECT with DISTINCT on multiple columns. You can use the count() function in a select statement with distinct on multiple columns to count the distinct rows. Here is an example: SELECT COUNT(*) FROM ( SELECT DISTINCT agent_code, ord_amount,cust_code FROM orders WHERE agent_code='A002'); Output: SELECT count(*) AS distinct_service_type FROM (SELECT distinct service_type FROM service_table) a; In this case, the first stage of the query implementing DISTINCT can use more than one reducer. In the second stage, the mapper will have less output just for the COUNT purpose since the data is already unique after implementing DISTINCT. Oct 29, 2013 · And: With or without the parentheses, SELECT DISTINCT does not know that you really want it to concentrate on column1 or (column1 and column2) ignoring the other columns. SELECT DISTINCT is a “row operator”, not a function, and not magic. SELECT count(*) AS distinct_service_type FROM (SELECT distinct service_type FROM service_table) a; In this case, the first stage of the query implementing DISTINCT can use more than one reducer. In the second stage, the mapper will have less output just for the COUNT purpose since the data is already unique after implementing DISTINCT.