2008年9月10日 · UPDATE sales s SET status = 'ACTIVE' WHERE NOT EXISTS ( SELECT FROM sales s1 -- SELECT list can be empty for EXISTS WHERE s.saleprice = s1.saleprice AND s.saledate = s1.saledate AND s.id <> s1.id -- except for row itself ) AND s.status IS DISTINCT FROM 'ACTIVE'; -- avoid empty updates. see below

Distinct will do a distinct on the entire row as @MarkByers has indicated in his answer. For those who want to test the above, here is a script that will create a table with 3 columns and then fill it with data. Both (distinct and group by) will return the same resultset.

2016年8月24日 · SELECT top 50 column1, column2,column3,column4 FROM (Select Distinct column1,column2, column3, column4 from Table Where Column2>= '2016-07-01' ) Order By Column2; The result is not what I am expecting. I want to make columns Column1, Column2, Column3, Column4 all distinct, meaning each column should have no two identical values. Is …

2012年8月30日 · What I'm trying to do is to select the distinct values of ALL of these 4 columns in my table (only the distinct values). I tried stuff like: SELECT DISTINCT a,b,c,d FROM my_table; SELECT DISTINCT a,b,c,d FROM my_table GROUP BY a,b,c,d; None of those worked. Can anybody help out here? Thank you

2011年5月25日 · SELECT DISTINCT FIELD1, FIELD2, FIELD3 FROM TABLE1 works if the values of all three columns are unique in the table. If, for example, you have multiple identical values for first name, but the last name and other information in the selected columns is different, the record will be included in the result set.

2009年9月24日 · Select count(1) from (select distinct col1, col2 from mytable where code = a.code...) --this doesn't work because the sub-query doesn't know what "a" is So eventually I figured out I could cheat, and combine the columns:

Say I have a dataframe df with two or more columns, is there an easy way to use unique() or other R function to create a subset of unique combinations of two or more columns? I know I can use sqldf() and write an easy "SELECT DISTINCT var1, var2, ... varN" query, but I am looking for an R way of doing this.

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 the result will be unique in terms of the combination of the select query columns. In OP's question, the below two result rows are already ...

2021年11月4日 · For example: if you have a two numeric column then using COUNT(DISTINCT col1 || col2) will group together 1||23 and 12||3 and count them as one group. You could use COUNT(DISTINCT col1 || '-' || col2) but if the columns are string values and you have 'ab-'||'-'||'c' and 'ab'||'-'||'-c' then, once again, they would be identical once concatenated.

2021年11月16日 · select distinct applies to all columns in the row. So, you can do: select distinct col1, col2, col3 from t; If you only want col1 and col2 to be distinct, then group by works: select col1, col2, min(col3) from t group by col1, col2; Or if you want random rows, you can use row_number(). For instance: