View Naming Conventions
A view name has the same naming conventions as a table name, and shares the same name set. Therefore, you cannot use the same name for a table and a view in the same schema. Attempting to do so results in an SQLCODE -201 error. To determine if a table already exists in the current namespace, use the $SYSTEM.SQL.Schema.TableExists("schema.tname")Opens in a new tab method. A class that projects a table definition and a view definition with the same name also generates an SQLCODE -201 error.
View names follow identifier conventions, subject to the restrictions below. By default, view names are simple identifiers. A view name should not exceed 128 characters. View names are not case-sensitive.
InterSystems IRIS uses the view name to generate a corresponding class name. A class name contains only alphanumeric characters (letters and numbers) and must be unique within the first 96 characters. To generate this class name, InterSystems IRIS first strips punctuation characters from the view name, and then generates a identifier that is unique within the first 96 characters, substituting an integer (beginning with 0) for the final character when needed to create a unique class name. InterSystems IRIS generates a unique class name from a valid view name, but this name generation imposes the following restrictions on the naming of views:
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A view name must include at least one letter. Either the first character of the view name or the first character after initial punctuation characters must be a letter.
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InterSystems IRIS supports 16-bit (wide) characters for view names. A character is a valid letter if it passes the $ZNAME test.
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If the first character of the view name is a punctuation character, the second character cannot be a number. This results in an SQLCODE -400 error, with a %msg value of “ERROR #5053: Class name 'schema.name' is invalid” (without the punctuation character). For example, specifying the view name %7A generates the %msg “ERROR #5053: Class name 'User.7A' is invalid”.
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Because generated class names do not include punctuation characters, it is not advisable (though possible) to create a view name that differs from an existing view or table name only in its punctuation characters. In this case, InterSystems IRIS substitutes an integer (beginning with 0) for the final character of the name to create a unique class name.
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A view name may be much longer than 96 characters, but view names that differ in their first 96 alphanumeric characters are much easier to work with.
A view name can be qualified or unqualified.
A qualified view name (schema.viewname) can specify an existing schema or a new schema. If it specifies a new schema, the system creates that schema.
An unqualified view name (viewname) takes the default schema name.
