postgresql distinct column
Using a completely different query you can force PostgreSQL to use an index and get the equivalent of DISTINCT column.,SELECT DISTINCT ON (name) name, id, tablename FROM ( SELECT name, ... Just specify to only do distinct on the name by using your query as a sub-query. ,To do a distinct on only one (or n) column(s): select distinct on (name) name, col1, col2 from names. This will return any of the rows containing the name. , select distinct on (news_id) * from x order by news_id, history_id desc; ... which is usually more flexible but a bit slower than using distinct on, You can use PostgreSQL's Aggregate Functions SELECT type ,string_agg(NAME, ',') "name" FROM eatable GROUP BY type;. Result:, DISTINCT can be also used on multiple columns at once; in that case it will evaluate the duplicates based on the combination of values of those ...,, I don't think your code should throw an error in Postgres. However, it won't do what you expect without an order by : select distinct on ..., 3 powerful uses of DISTINCT in PostgreSQL. ... Column | Type | Modifiers ... SELECT DISTINCT eliminates duplicate rows from the result.
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 postgresql distinct column 相關參考資料
Create an index over distinct values of a column in PostgreSQL ...
Using a completely different query you can force PostgreSQL to use an index and get the equivalent of DISTINCT column. https://stackoverflow.com How to ignore a column for select distinct in postgresql? - Stack ...
SELECT DISTINCT ON (name) name, id, tablename FROM ( SELECT name, ... Just specify to only do distinct on the name by using your query as a sub-query. https://stackoverflow.com Postgres: Distinct but only for one column - Stack Overflow
To do a distinct on only one (or n) column(s): select distinct on (name) name, col1, col2 from names. This will return any of the rows containing the name. https://stackoverflow.com Postgres: Distinct but only for one column and latest one - Stack ...
select distinct on (news_id) * from x order by news_id, history_id desc; ... which is usually more flexible but a bit slower than using distinct on https://stackoverflow.com postgresql - distinct only on one column - Stack Overflow
You can use PostgreSQL's Aggregate Functions SELECT type ,string_agg(NAME, ',') "name" FROM eatable GROUP BY type;. Result: https://stackoverflow.com PostgreSQL DISTINCT ON · zaiste.net
DISTINCT can be also used on multiple columns at once; in that case it will evaluate the duplicates based on the combination of values of those ... https://zaiste.net PostgreSQL SELECT DISTINCT By Practical Examples
http://www.postgresqltutorial. Select all columns from rows distinct on one column - Stack Overflow
I don't think your code should throw an error in Postgres. However, it won't do what you expect without an order by : select distinct on ... https://stackoverflow.com The many faces of DISTINCT in PostgreSQL – Statuscode – Medium
3 powerful uses of DISTINCT in PostgreSQL. ... Column | Type | Modifiers ... SELECT DISTINCT eliminates duplicate rows from the result. https://medium.com |