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# sql count distinct for all columns

In aggregates, we consider various types of functions like count, max, avg, min, and sum. Count by multiple selects. You may want to find the number of distinct values in a column, or in a result set. This outputs “Distinct Count of Department & Salary: 8”. DISTINCT can be used with COUNT. The general syntax is. Here is an example : select count(*) from ( SELECT distinct agent_code, ord_amount,cust_code FROM orders WHERE agent_code='A002'); Output: Outputs of the said SQL statement shown here is taken by using Oracle Database 10g Express Edition. At the least this should not be inserted in that table that you use for the statistics, because you would have a lot of redundant rows, the only difference being the distinct column value. This cursor gives the distinct count for all colums in every table in the database, I need to get each distinct column value for every column in all tables in the database, I understand this may take a long time to run but it is most valueable to me and I am not too familiar with cursors. Most, if not all, relational databases contain a data dictionary or system catalog. Often we want to count the number of distinct items from this table but the distinct is over multiple columns. This table are having 1000 records. You can definitely count the number of columns of a table using an SQL query, however, the exact query will vary by the exact database product. SparkByExamples.com is a BigData and Spark examples community page, all examples are simple and easy to understand and well tested in our development environment using Scala and Python (PySpark), | { One stop for all Spark Examples }, Click to share on Facebook (Opens in new window), Click to share on Reddit (Opens in new window), Click to share on Pinterest (Opens in new window), Click to share on Tumblr (Opens in new window), Click to share on Pocket (Opens in new window), Click to share on LinkedIn (Opens in new window), Click to share on Twitter (Opens in new window), Spark SQL – Get distinct multiple columns. Transact SQL :: How To Get Distinct Count Of All Columns Of A Table Dec 3, 2015. This examples are tested with Oracle. They are using standard SQL so they will work also on MySQL or any other DB which is following SQL standards. Note that countDistinct() function returns a value in a Column type hence, you need to collect it to get the value from the DataFrame. Now I want to know the distinct value count of all these 6 columns as well as normal count. In order to use this function, you need to import first using, "import org.apache.spark.sql.functions.countDistinct". Get distinct all columns On the above DataFrame, we have a total of 10 rows and one row with all values duplicated, performing distinct on this DataFrame should get us 9 as we have one duplicate. The SQL SELECT DISTINCT syntax. Any help will be gratly appreciated. FROM table-name. You can count all rows (using ALL), or distinct values of the expression (using DISTINCT). DISTINCT for multiple columns is not supported. Before we start, first let’s create a DataFrame with some duplicate rows and duplicate values in a column. Next, we issue SQL*plus breaks to get only the distinct values for every column in the result set: select deptno, loc, job, sal, ename from lsc_emp join lsc_dept using (deptno) order by deptno,loc,job,sal,ename; The following query returns the number of distinct values in the primary_key column of the date_dimension table: DISTINCT operates on a single column. SELECT COUNT (DISTINCT column-name) FROM table-name. Here's one option using a separate COUNT DISTINCT for each column: SELECT COUNT (DISTINCT tel) gender_count, COUNT (DISTINCT CASE WHEN gender = 'male' THEN tel END) male_count, COUNT (DISTINCT CASE WHEN gender = 'female' THEN tel END) female_count This function returns the number of distinct elements in a group. Count function is a part of the SQL Server's aggregate functions. Unless you want a comma separated list of all values in a text field. Here is an example: SELECT COUNT(*) FROM ( SELECT DISTINCT agent_code, ord_amount,cust_code FROM orders WHERE agent_code='A002'); Output: COUNT(*) ----- 6 Pictorial presentation: Practice SQL … One of the users had a very interesting scenario where he had to change one of their employee's email address for technical reasons but before he changes that he needed to count in every single place where the email exists. In order to use this function, you need to import first using, "import org.apache.spark.sql.functions.countDistinct" Values for all columns selecting the distinct rows I know this is the expected for... Anyway... ( Unlock this solution with a 7-day Free Trial ), https: //www.experts-exchange.com/questions/21180306/Find-distinct-value-for-all-table-columns-in-a-database.html ) calculate... High tech and professional accomplishments as an expert in a text field accomplishments as an in... 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