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How do you find second highest salary in Hive?
Below is the HQL Query to get the second maximum salary from Employee table. select firstname,salary from (select firstname, salary from employee sort by salary desc limit 2) result sort by salary limit 1; Happy Learning!!
How do you duplicate records in Hive?
select count(distinct primary_key1, primary_key2) from mytable; With this approach, for one of my table total row count derived using first query is 3500 and second query gives row count 2700. So it tells us that 3500 – 2700 = 800 rows are duplicate.
How to prevent duplicate records from my table?
The queries below delete some duplicate records, and alters table by adding unique constraint on column ename. DELETE a FROM Employee a LEFT JOIN ( SELECT ename, MIN (eno) minEno FROM Employee GROUP BY ename ) b ON a.eno = b.minEno WHERE b.minEno IS NULL; ALTER TABLE employee ADD CONSTRAINT emp_unique UNIQUE (ename);
How to prevent MySQL double insert ( duplicate entry )?
How to prevent MySQL double insert (duplicate entry)? To prevent duplicate entry, add constraint UNIQUE. Let us first create a table − Insert records in the table using insert command. When we will try to the same record again, then the “Duplicate entry” error will be visible −
How to delete duplicate records from mysql table?
You only need to add unique constraint on column ename since eno will always be unique due to AUTO_INCREMENT. In order to add unique constraint, you need to do some cleanups on your table. The queries below delete some duplicate records, and alters table by adding unique constraint on column ename.
How to avoid duplicates in an Excel spreadsheet?
You can avoid inserting duplicates with this simple, one line of code: INSERT INTO Delegates (MemNo, FromYr, ToYr) SELECT @MemNo, @FromYr, @ToYr WHERE NOT EXISTS (SELECT 1 FROM Delegates d WHERE d.MemNo=@MemNo AND d.FromYr=@FromYr)