- Can we use MAX function in where clause?
- Which join is faster in SQL?
- Which is faster truncate or drop?
- Is Grant DDL or DML?
- Which is faster truncate or delete?
- Can we use count in where clause?
- What does having clause do in SQL?
- How do I quickly query in SQL?
- Can we use group by and having clause together?
- How do I select duplicate rows in SQL?
- What is the difference between group by and having?
- What is the difference between having and where?
- What is difference between drop and delete?
- Can we use two group by in same query?
- Is a view faster than a query?
- Can we use where clause with aggregate functions?
- Which is faster where or having?
Can we use MAX function in where clause?
MAX() function with Having The SQL HAVING CLAUSE is reserved for aggregate function.
The usage of WHERE clause along with SQL MAX() have also described in this page.
The SQL IN OPERATOR which checks a value within a set of values and retrieve the rows from the table can also be used with MAX function..
Which join is faster in SQL?
It’s because SQL Server wants to do a hash match for the INNER JOIN , but does nested loops for the LEFT JOIN ; the former is normally much faster, but since the number of rows is so tiny and there’s no index to use, the hashing operation turns out to be the most expensive part of the query.
Which is faster truncate or drop?
TRUNCATE is a DDL(Data Definition Language) command. It is used to delete all the tuples from the table. Like the DROP command, the TRUNCATE command also does not contain a WHERE clause. The TRUNCATE command is faster than both the DROP and the DELETE command.
Is Grant DDL or DML?
Data definition language (DDL) statements let you to perform these tasks: Create, alter, and drop schema objects. Grant and revoke privileges and roles. Analyze information on a table, index, or cluster.
Which is faster truncate or delete?
TRUNCATE is faster than DELETE , as it doesn’t scan every record before removing it. TRUNCATE TABLE locks the whole table to remove data from a table; thus, this command also uses less transaction space than DELETE . Unlike DELETE , TRUNCATE does not return the number of rows deleted from the table.
Can we use count in where clause?
SQL COUNT( ) with where clause The WHERE clause can be used along with SQL COUNT() function to select specific records from a table against a given condition.
What does having clause do in SQL?
The HAVING Clause enables you to specify conditions that filter which group results appear in the results. The WHERE clause places conditions on the selected columns, whereas the HAVING clause places conditions on groups created by the GROUP BY clause.
How do I quickly query in SQL?
10 More Do’s and Don’ts for Faster SQL QueriesDo use temp tables to improve cursor performance. … Don’t nest views. … Do use table-valued functions. … Do use partitioning to avoid large data moves. … If you must use ORMs, use stored procedures. … Don’t do large ops on many tables in the same batch. … Don’t use triggers. … Don’t cluster on GUID.More items…•
Can we use group by and having clause together?
HAVING Clause always utilized in combination with GROUP BY Clause. HAVING Clause restricts the data on the group records rather than individual records. WHERE and HAVING can be used in a single query.
How do I select duplicate rows in SQL?
To select duplicate values, you need to create groups of rows with the same values and then select the groups with counts greater than one. You can achieve that by using GROUP BY and a HAVING clause.
What is the difference between group by and having?
The main difference between WHERE and HAVING clause comes when used together with GROUP BY clause, In that case WHERE is used to filter rows before grouping and HAVING is used to exclude records after grouping. … You can even use WHERE clause without HAVING or GROUP BY, as you have seen it many times.
What is the difference between having and where?
To summarize the difference between WHERE and HAVING: WHERE is used to filter records before any groupings take place. HAVING is used to filter values after they have been groups. Only columns or expressions in the group can be included in the HAVING clause’s conditions…
What is difference between drop and delete?
DELETE is a Data Manipulation Language command, DML command and is used to remove tuples/records from a relation/table. Whereas DROP is a Data Definition Language, DDL command and is used to remove named elements of schema like relations/table, constraints or entire schema. … DELETE is DML. DROP is DDL.
Can we use two group by in same query?
SELECT Statement: The GROUP BY Clause in SQL A GROUP BY clause can contain two or more columns—or, in other words, a grouping can consist of two or more columns. We illustrate this with two examples.
Is a view faster than a query?
Views make queries faster to write, but they don’t improve the underlying query performance. … In short, if an indexed view can satisfy a query, then under certain circumstances, this can drastically reduce the amount of work that SQL Server needs to do to return the required data, and so improve query performance.
Can we use where clause with aggregate functions?
You cannot use aggregate functions in a WHERE clause or in a JOIN condition. However, a SELECT statement with aggregate functions in its select list often includes a WHERE clause that restricts the rows to which the aggregate is applied.
Which is faster where or having?
Both the statements will be having same performance as SQL Server is smart enough to parse both the same statements into a similar plan. So, it does not matter if you use WHERE or HAVING in your query. … “WHERE” is faster than “HAVING”!