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Can you GROUP BY primary key in SQL?
Essentially this means grouping by the primary key of a table results in no change in rows to that table, therefore if we group by the primary key of a table, we can call on all columns of that table with no aggregate function.
Can I GROUP BY all columns?
If you group by all columns, you are just requesting that duplicate data be removed. Using DISTINCT is not always possible directly.
Can I use SELECT * with GROUP BY?
Cannot use an aggregate or a subquery in an expression used for the group by list of a GROUP BY clause. The original idea was to create the table in beginning of the query, so the (SELECT * FROM #TBL) could be used on the query itself, instead of defining the names on each GROUP BY.
What happens when you group a table by primary key?
Essentially this means grouping by the primary key of a table results in no change in rows to that table, therefore if we group by the primary key of a table, we can call on all columns of that table with no aggregate function.
Is there way to group by key to get this result?
Closed 4 years ago. Is there a way to group by the key to get this result? This is not correct I know that, because I should group by all the columns that I need to show. Is there a solution for this problem? Notice that the order by clause determines which row will win the ties. where min (id) is the function that influences which result you get.
When is group by primary key a functional dependency?
A functional dependency exists if the grouped columns (or a subset thereof) are the primary key of the table containing the ungrouped column. Grouping by primary key results in a single record in each group which is logically the same as not grouping at all / grouping by all columns, therefore we can select all other columns.
How to select column not in group by clause?
The columns in the result set of a select query with group by clause must be: an expression used as one of the group by criteria , or an aggregate function , or So, you can’t do what you want to do in a single, simple query.