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DROP AGGREGATE (Transact-SQL)
Removes a user-defined aggregate function from the current database. User-defined aggregate functions are created by using CREATE AGGREGATE.
Transact-SQL Syntax Conventions
DROP AGGREGATE [ schema_name . ] aggregate_name
Is the name of the schema to which the user-defined aggregate function belongs.
Is the name of the user-defined aggregate function you want to drop.
DROP AGGREGATE does not execute if there are any views, functions, or stored procedures created with schema binding that reference the user-defined aggregate function you want to drop.
To execute DROP AGGREGATE, at a minimum, a user must have ALTER permission on the schema to which the user-defined aggregate belongs, or CONTROL permission on the aggregate.
The following example drops the aggregate
DROP AGGREGATE dbo.Concatenate