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Tag: sqlhadoophive. I am new to running Hive queries. I have a requirement to concatenate all the rows from a group by query into a single comma separated field. There was an answer on stackoverflow showing that there is a limitation to do this based on the version of Hadoop, I am using.
So, I have two questions. Take this for a starter code : import numpy as np import matplotlib. So you want all distinct records from table1 paired with all records in table2? This is the sqlfiddle. It will produce the op you are expecting SQLFiddle select t1. You need to use some dynamic SQL I believe. Your server has magic quotes enabled and your local server not.
You have to JOIN them, if them have matched column in each other.
Pivot rows to columns in Hive
SQLite is an embedded database, i. It might be possible to import that log file into a database file, but the whole point of having a database is to store the data, which is neither a direct goal When creating a foreign key constraint, you can also decide what should happen with the constraints.
The cascade identifies to the I have tested your code, I do not see any issues except for the fact, your For statement is a bit off and that you needed to set the db object. Try this code. Have a separate table with one row that contains the mainOfferName of the row that you want. Then query as: select yt. Perhaps this is what you want? Key and SecondTable.We can see that there are null values and each resource is having multiple records. This is expected as we have not grouped this on resource id yet and for each resource, there may not be an entry for each quarter.
We can prettify our results in step two by modifying our query with CASE statements. I like to learn and try out new things. I have started blogging about my experience while learning these exciting technologies.
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How to Convert Rows to Columns and Back Again with SQL (Aka PIVOT and UNPIVOT)
Save my name, email, and website in this browser for the next time I comment. Skip to content Pivot rows to columns in Hive.
Hello everyone. In this article, we will learn how can we pivot rows to columns in the Hive. From this table, you want to show data like this. Step I — Using Case statments First, we can use case statements to transpose required rows to columns. Stay updated with latest blogs. Text Input. I consent to having this website store my submitted information so they can respond to my inquiry.
Mahesh Mogal. Let Us Connect 17 Followers. Leave a Comment Cancel Reply Your email address will not be published. Get blogs delivered to your email directly. Share via. Facebook Messenger. Copy Link.The Olympics is over for another year. But there's still plenty of time for SQL-style data wrangling of the results! To do this, I've compiled a table of medal winners from Rio for each sport:. This is great when looking for a specific result.
But what everyone really wants to know how their country fared overall. To get this you need to convert the table above to the final medal table:. To do this, you need to count the number of gold, silver and bronze rows for each country. Then create new columns to hold the results. This post will teach you. You'll also learn various row and column transformations with SQL including:.
If you want to play along you can access the scripts in LiveSQL.
How to Convert Rows to Columns and Back Again with SQL (Aka PIVOT and UNPIVOT)
Or you can nab the create table scripts at the bottom of this post. Oracle Database 11g introduced the pivot operator. This makes switching rows to columns easy. To use this you need three things:. The value in the new columns must be an aggregate. For example, count, sum, min, etc. Place a pivot clause containing these items after the table name, like so:. Hmmm, that's not right!
You wanted the total medals for each country. This is giving the results per athlete! This is because Oracle adds an implicit group by for all the columns not in the pivot clause.
To avoid this, use an inline view that selects just the columns you want in the results:. This is looking promising. But it's still not right. China didn't finish second.
Team GB did! And all countries have too many medals. In these cases multiple people win a medal. And each person has their own entry in the winners table.Tag: sqlhadoophive. I am new to running Hive queries. I have a requirement to concatenate all the rows from a group by query into a single comma separated field.
There was an answer on stackoverflow showing that there is a limitation to do this based on the version of Hadoop, I am using. So, I have two questions. This could be done using user defined variable which is faster as already mentioned in the previous answer. This needs creating incremental variable for each group depending on some ordering.
And from the given data set its user and date. The issue is that you are using the alias C where you should not, with the count function. This: C. Count C. This is the sqlfiddle. It will produce the op you are expecting SQLFiddle select t1. Perhaps this is what you want? Key and SecondTable. You need to use some dynamic SQL I believe. The is shown in MS Excel when the data in a cell is too long for the column width Your server has magic quotes enabled and your local server not.
So you want all distinct records from table1 paired with all records in table2?
SQL Server is correct in what it's doing as you are requesting an additional row to be returned which if ran now would return "" Your distinct only works on the first select you've done so these are your options: 1 Use cte's with distincts with subq1 syear, eyear, Delete the value and retype.
Demo here Alternatively, the following can What I would do here is write a select statement that pulls all of the columns you need first. You will have to do a full outer join simulated by a union of left and right joins because some Well, are you looking for a hashcode like this? ToBase64String g. On the linked post there are many other useful answers. Please take a look! Other useful links I can explain ColumnX AND t2. Take this for a starter code : import numpy as np import matplotlib.
I have tested your code, I do not see any issues except for the fact, your For statement is a bit off and that you needed to set the db object. Try this code. You have to JOIN them, if them have matched column in each other. The easiest way would be to pad the keys to a fixed length. Although you could keep your path trimmed for readability and create an extra padded field for sortingSuppose, you have one table in hive with one column and you want to split this column into multiple columns and then store the results into another Hive table.
Insert data into connections columns, String should be comma separated. For e. Create an output table where you want to store split values. Run below command in the hive:. There is a built-in function SPLIT in the hive which expects two arguments, the first argument is a string and the second argument is the pattern by which string should separate.
It will convert String into an array, and desired value can be fetched using the right index of an array. Inner query is used to get the array of split values and the outer query is used to assign each value to a separate column. What should i do for that? You must be logged in to post a comment.
Split one column into multiple columns in hive In: Hive. Share Tweet LinkedIn. Subscribe to our newsletter. Leave a Reply Cancel reply You must be logged in to post a comment. Load CSV file in hive Requirement If you have comma separated file and you want to create a table in the hive on top of it Split one column into multiple columns in hive Requirement Suppose, you have one table in hive with one column and you want to split this column in This file contains some empty tag.
Partitioning in Hive Requirement Suppose there is a source data, which is required to store in the hive partitioned table The requirement is to load JSON Export hive data into file Requirement You have one hive table named as infostore which is present in bdp schema.
One more appl Join in pig Requirement You have two tables named as A and B and you want to perform all types of join in Pig. String to Date conversion in hive Requirement: Generally we receive data from different sources which usually have different types ofOne of the primary functions of a Business Intelligence team is to enable business users with an understanding of data created and stored by business systems.
Understanding the data should give business users an insight into how the business is performing. A typical understanding of data within an insurance industry could relate to measuring the number of claims received vs successfully processed claims.
Such data could be stored in source system as per the layout in Table 1 :. Although each data entry in Table 1 has a unique RecKey identifier, it all still relates to a single policy claim policy Pol Thus, a correct representation of this data ought to be in a single row that contains a single instance of policy Pol as shown in Table 2 :. The objective of this article is to demonstrate different SQL Server T-SQL options that could be utilised in order to transpose repeating rows of data into a single row with repeating columns as depicted in Table 2.
Some of the T-SQL options that will be demonstrated will use very few lines of code to successfully transpose Table 1 into Table 2 but may not necessary be optimal in terms query execution. Script 1 shows how a Pivot function can be utilised. The results of executing Script 1 are shown in Figure 1as it can be seen, the output is exactly similar to that of Table 2. Furthermore, as we add more policy numbers in our dataset i. Polwe are able to automatically retrieve them without making any changes to Script 1.
This is because the Pivot function works with only a predefined list of possible fields. However, imagine if business later decides to add more documents that are required to process a claim? It would mean that you need to update your Pivot script and manually add those fields. Thus, although transposing rows using Pivot operator may seem simple, it may later be difficult to maintain. The actual estimated plan depicted in Figure 4indicates that only a single scan was made against the base table with a majority of the cost at Although the general consensus in the professional community is to stay away from SQL Server Cursors, there are still instances whereby the use of cursors is recommended.
I suppose if they were totally useless, Microsoft would have deprecated their usage long ago, right? Anyway, Cursors present us with another option to transpose rows into columns.
Script 2 displays a T-SQL code that can be used to transpose rows into columns using the Cursor function. Execution of Script 2 lead to the result set displayed in Figure 6 yet, the Cursor option uses far more lines of code than its T-SQL Pivot counterpart. Similar to the Pivot function, the T-SQL Cursor has the dynamic capability to return more rows as additional policies i.
Pol are added into the dataset, as shown in Figure 7 :. The major limitation of transposing rows into columns using T-SQL Cursor is a limitation that is linked to cursors in general — they rely on temporary objects, consume memory resources and processes row one at a time which could all result into significant performance costs.
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Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Problem: I am trying to convert date from rows to columns as week numbers and get the price from the highest week number and call it givenPrice.
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