How to select unique records by SQL - Stack Overflow
DISTINCT keyword is supposed to be applied to all the columns in the select query and not just to the column next to which DISTINCT keyword is written. So, basically, it means that every row returned in …
sql - DISTINCT for only one column - Stack Overflow
Feb 19, 2017 · When you use DISTINCT think of it as a distinct row, not column. It will return only rows where the columns do not match exactly the same.
How do I (or can I) SELECT DISTINCT on multiple columns?
Sep 10, 2008 · The problem with your query is that when using a GROUP BY clause (which you essentially do by using distinct) you can only use columns that you group by or aggregate functions.
sql - DISTINCT clause with WHERE - Stack Overflow
How can I use the DISTINCT clause with WHERE? For example: SELECT * FROM table WHERE DISTINCT email; -- email is a column name I want to select all columns from a table with distinct …
Using the distinct function in SQL - Stack Overflow
3 I have a SQL query I am running. What I was wanting to know is that is there a way of selecting the rows in a table where the value in on one of those columns is distinct? When I use the distinct …
sql - DISTINCT e GROUP BY, qual a diferença entre ambas as …
Aug 11, 2017 · No SQL Server não há diferença de performance, pois resultará no mesmo plano de execução. "Um DISTINCT e GROUP BY geralmente geram o mesmo plano de consulta, de modo …
Is there any difference between GROUP BY and DISTINCT?
Oct 3, 2008 · If you are using a GROUP BY without any aggregate function then internally it will treated as DISTINCT, so in this case there is no difference between GROUP BY and DISTINCT.
MySQL: Select DISTINCT / UNIQUE, but return all columns?
May 25, 2011 · You have selected the distinct column in the subquery but the where clause gets all those columns with that value. So the query is as good as writing 'select * from table' unless 'field' …
sql - Counting DISTINCT over multiple columns - Stack Overflow
Sep 24, 2009 · When using SQL Server, (as this question is tagged for), your initially proposed subquery method is the most accurate way to count DISTINCT values over multiple fields.
SQL to find the number of distinct values in a column
Apr 5, 2019 · SELECT COUNT(DISTINCT column_name) AS some_alias FROM table_name This will count only the distinct values for that column.