Distinct many columns oracle

Use an appropriate query style depending on what you want to achieve. The are sorted in ascending order by city. In this example, both values the product_id and quantity columns are used for evaluating the uniqueness of the rows in the result set. Thanks for the question, Rajneesh.

So with many aggregates the new columns will all have the same name. DISTINCT treats NULL values to be duplicates of each other. Right now there are duplicates in that column. Distinct Count of a Value across columns in the table. I Need the distinct count of countries across columns of the table i. I just needed to omit those non-duplicate valued columns from the select list of a distinct clause, which were trivial anyways.

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 column, COUNT(column). Oracle Database technologies. The following will make all three columns distinct. I want only the Job_ID column to be distinct.

Update: Tested all queries in SQLfiddle with 100K rows (and separate cases, one with few (25) distinct values and another with lots (around 25K values). A very simple query would be to use UNION DISTINCT. I think it would be most efficient if there is a separate index on each of the four columns It would be efficient with a separate index on each of the four columns , if Postgres had. Rate this: Please or sign in to vote.

SELECT one column, with multiple columns returned where other columns are same, mysql. By default aggregate functions use every input value. But most allow you to work on the unique values in the input. You do this with the keyword distinct. For example, you can find the number of different values in the colour column by passing distinct colour to count.

There are three colours (re green, and blue). Learn more about the COUNT function in this article. The purpose of the COUNT function is to count the number of rows returned in a SELECT statement.

LONG and LONG RAW columns cannot be indexed. The size of a single index entry cannot exceed roughly one-half (minus some overhead) of the available space in the data block. So that means I will get rows for the given ItemVendorID. Say RecItem has 2 and and VendorAdjustment has just 3. But the RecAmount should add up to 50.

ALL_TAB_ COLUMNS describes the columns of the tables, views, and clusters accessible to the current user. To gather statistics for this view, use the ANALYZE SQL statement or the DBMS_STATS package. DBA_TAB_ COLUMNS describes the columns of all tables, views, and clusters in the database.

We cannot exactly control which ones will appear in the result set, and we might get that we haven’t intended. I have a table having some 2plus no of columns how to find the total no of columns exactly? In the table I have the user_id and the office_id.

How can I count how many distinct users have visited all locations.