difference between having and group by clause ?

Having Clause is basically used only with the GROUP BY function in a query. WHERE Clause is applied to each row before they are part of the GROUP BY function in a query (More...)

Both Clause are used to check the Condition at the time of Retrival of records in Database.
WHERE Clause is applied to each row before they are part of the GROUP BY function in a query.
Having Clause is basically used only with the GROUP BY function in a query. (More...)

Having Clause is basically used only with the GROUP BY function in a query. WHERE Clause is applied to each row before they are part of the GROUP BY function in a query (More...)

Having Clause is basically used only with the GROUP BY function in a query.
WHERE Clause is applied to each row before they are part of the GROUP BY function in a query.
(More...)

They specify a search condition for a group or an aggregate. But the difference is that HAVING can be used only with the SELECT statement. HAVING is typically used in a GROUP BY clause. When GROUP BY is not used, HAVING behaves like a WHERE clause. Having Clause is basically used only with the GROUP BY function in a query whereas WHERE Clause is applied to each row before they are part of the GROUP BY function in a query. (More...)

WHERE clause:
Restriction statement.
Having clause:
Using after retrieving the Data
(More...)

requires creation of Temporary tables to process the results of the query (More...)

Where clause is used for check condition or fetch specfic values

select * from employee where empid=1001

Having clause is used for Grouping Group by Clause.

avg,max,count,min....


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.Delete table is a logged operation, so the deletion of each row gets logged in the transaction log, which makes it slow.

. Truncate table also deletes all the rows in a table, but it won't log the deletion of each row, instead it logs the de-allocation of the data pages of the table, which makes it faster. Of course, truncate table cannot be rolled back.

. Truncate table is functionally identical to delete statement with no "where clause" both remove all rows in the table. But truncate table is faster and uses fewer system and transaction log resources than delete.

. Truncate table removes all rows from a table, but the table structure and its columns, constraints, indexes etc., remains as it is.

. In truncate table the counter used by an identity column for new rows is reset to the seed for the column.

. If you want to retain the identity counter, use delete statement instead.

. If you want to remove table definition and its data, use the drop table statement.

. You cannot use truncate table on a table referenced by a foreign key constraint; instead, use delete statement without a where clause. Because truncate table is not logged, it cannot activate a trigger.

. Truncate table may not be used on tables participating in an indexed view. (More...)

assembly manifest - An integral part of every assembly that renders the assembly self-describing. The assembly manifest contains the assembly's metadata. The manifest establishes the assembly identity, specifies the files that make up the assembly implementation, specifies the types and resources that make up the assembly, itemizes the compile-time dependencies on other assemblies, and specifies the set of permissions required for the assembly to run properly. This information is used at run time to resolve references, enforce version binding policy, and validate the integrity of loaded assemblies. The self-describing nature of assemblies also helps makes zero-impact install and XCOPY deployment feasible.

metadata - Information that describes every element managed by the common language runtime: an assembly, loadable file, type, method, and so on. This can include information required for debugging and garbage collection, as well as security attributes, marshaling data, extended class and member definitions, version binding, and other information required by the runtime. (More...)