COMMENT Syntax | SQL Statements | Teradata Vantage - 17.05 - COMMENT Syntax (Comment-Retrieving Form) - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Manipulation Language

Product
Advanced SQL Engine
Teradata Database
Release Number
17.05
Release Date
January 2021
Content Type
Programming Reference
Publication ID
B035-1146-175K
Language
English (United States)
COMMENT [ON] [ object_kind_1 | object_kind_2 ]
  [ database_name. | user_name. ] object_name [;]

Syntax Elements

object_kind_1
Mandatory database object kind specification.
The valid specifications for object_kind_1 are not all database objects. Triggers and views, for example, are definitions of actions or conceptual groups rather than database objects.
You must specify the following database object kinds to retrieve a comment for the kind of object they represent.
  • COLUMN
  • FUNCTION
  • GLOP SET
  • GROUP
  • MACRO
  • METHOD
  • PROCEDURE
  • PROFILE
  • ROLE
  • TRIGGER
  • TYPE
  • VIEW
object_kind_2
Optional database object kind specification.
You can specify the following database object kinds to retrieve a comment for the kind of object they represent, but they are optional.
  • DATABASE
  • TABLE
  • USER
  • FILE
The semantics of the COMMENT statement require that if you specify an object kind, you must specify the keyword TABLE for any hash or join index whose comment you want to retrieve; however, because TABLE is not a mandatory object kind specification, you are not required to specify it.
If you omit the object_kind when you retrieve a comment for a file, the object_name must contain the whole path to the file, for example, dbname.uifname.
database_name
user_name
Containing database or user for object_name if it is not contained by the current database or user.
You cannot specify a database name or user name if object_kind is GROUP.
For the rules to use in naming database objects, see Teradata Vantage™ - SQL Fundamentals, B035-1141.
object_name
Name of the object for which a comment is to be retrieved, including:
  • Parameter in a macro, stored procedure, or user-defined function.
  • Column in a user base table, error table, hash index, join index, or view.
  • Specific function, macro, profile, role, stored procedure, base table, error table, hash index, join index, trigger, or view name contained by a database or user.
  • Database or user.
  • UDT. You can retrieve a comment on a particular attribute of a structured UDT by specifying database_name.udt_name.attribute_name.
  • A method. You must use the specific method name.
  • A GLOP set.
If you do not precede the object name with an object kind keyword, the system attempts to deduce the object from the level of qualification in the name. Use the fully-qualified name to avoid ambiguity.
Let x.y.z indicate the qualification hierarchy, with x being the highest, or coarsest grained, level and z the lowest, or most finely grained.
If you specify a hierarchy level of x, the specified object is implied to be one of the following:
  • Database
  • User
If you specify a hierarchy level of x.y, the specified object is implied to be one of the following:
  • Base table
  • Error table
  • GLOP set
  • Hash index
  • Join index
  • Macro
  • Profile
  • Role
  • Stored procedure
  • Trigger
  • User-defined function
  • View within database or user x.
If you specify a hierarchy level of x.y.z, the specified object is implied to be one of the following:
  • Macro parameter
  • Stored procedure parameter
  • Structured UDT attribute
  • Table column
  • UDF parameter
  • View column within GLOP set, UDF, UDT, macro, stored procedure, profile, role, base table, trigger, or view y contained in database or user x.