Can you use max without GROUP BY?
6 Answers. As per the error, use of an aggregate like Max requires a Group By clause if there are any non-aggregated columns in the select list (In your case, you are trying to find the MAX(Num) and then return the value(s) associated in the ID column).
Can we use having Without GROUP BY in SQL?
You can also use the having clause with the Transact-SQL extension that allows you to omit the group by clause from a query that includes an aggregate in its select list. These scalar aggregate functions calculate values for the table as a single group, not for groups within the table.
What can be used instead of GROUP BY in SQL?
select , from , where , union , intersect , minus , distinct , count , and , or , as , between .
Is GROUP BY mandatory for having?
So having doesn’t require group by . Having is applied after the aggregation phase and must be used if you want to filter aggregate results.
Can I use WHERE after GROUP BY?
The GROUP BY Statement in SQL is used to arrange identical data into groups with the help of some functions. … GROUP BY clause is used with the SELECT statement. In the query, GROUP BY clause is placed after the WHERE clause. In the query, GROUP BY clause is placed before ORDER BY clause if used any.
Which is faster joins or subqueries?
The advantage of a join includes that it executes faster. The retrieval time of the query using joins almost always will be faster than that of a subquery. By using joins, you can maximize the calculation burden on the database i.e., instead of multiple queries using one join query.
What is difference between GROUP BY and HAVING?
The HAVING clause is used instead of WHERE with aggregate functions. While the GROUP BY Clause groups rows that have the same values into summary rows. The having clause is used with the where clause in order to find rows with certain conditions.
What will be output for inner join?
Inner Join clause in SQL Server creates a new table (not physical) by combining rows that have matching values in two or more tables. … The result of this join will be a new result set that returns matching rows in both these tables.
Is GROUP BY or distinct faster?
DISTINCT creates a temporary table and uses it for storing duplicates. GROUP BY does the same, but sortes the distinct results afterwards. is faster, if you don’t have an index on profession . All of the answers above are correct, for the case of DISTINCT on a single column vs GROUP BY on a single column.
Is GROUP BY better than distinct?
There is no significantly difference between group by and distinct clause except the usage of aggregate functions. Both can be used to distinguish the values but if in performance point of view group by is better. When distinct keyword is used , internally it used sort operation which can be view in execution plan.
Can I use GROUP BY instead of distinct?
DISTINCT is used to filter unique records out of the records that satisfy the query criteria. The “GROUP BY” clause is used when you need to group the data and it should be used to apply aggregate operators to each group.
Can we use ORDER BY and GROUP BY in same query?
GROUP BY and ORDER BY can be used in the same query and it is NOT required that they be the same column. GROUP BY controls the way the data is organized for sumarization. ORDER BY simply sorts the rows of the result.
What is GROUP BY in SQL?
A GROUP BY statement in SQL specifies that a SQL SELECT statement partitions result rows into groups, based on their values in one or several columns. Typically, grouping is used to apply some sort of aggregate function for each group. The result of a query using a GROUP BY statement contains one row for each group.
What is self join?
SELF JOIN: As the name signifies, in SELF JOIN a table is joined to itself. That is, each row of the table is joined with itself and all other rows depending on some conditions. In other words we can say that it is a join between two copies of the same table.