Identifiers

Identifiers are names for database objects such as databases, tables, views, columns, indexes, triggers, procedures, defaults, rules, and cursors.

The limit for the length of object names or identifiers is 255 bytes for regular identifiers, and 253 bytes for delimited identifiers. The limit applies to most user-defined identifiers including table name, column name, index name and so on. Due to the expanded limits, some system tables (catalogs) and built-in functions have been expanded.

For variables, “@” count as 1 byte, and the allowed name for it is 254 bytes long.

Listed below are the identifiers, system tables, and built-in functions that are affected these limits.

Most user-defined SAP ASE identifiers can be a maximum of 255 bytes in length, whether single-byte or multibyte characters are used. Others can be a mximum of 30 bytes. Refer to the Transact-SQL User’s Guide for a list of both 255-byte and 30-byte identifiers.

The first character of an identifier must be either an alphabetic character, as defined in the current character set, or the underscore (_ ) character.

Subsequent characters can include letters, numbers, the symbols #, @, _, and currency symbols such as $ (dollars), ¥ (yen), and £ (pound sterling). Identifiers cannot include special characters such as !, %, ^, &, *, and . or embedded spaces.

You cannot use a reserved word, such as a Transact-SQL command, as an identifier.

You cannot use the dash symbol ( – ) as an identifier.

• Short Identifiers
  The maximum length for these identifiers is 30 bytes:
• Tables Beginning With # (Temporary Tables)
  Tables with names that begin with the pound sign (#) are temporary tables. You cannot create other types of objects with names that begin with the pound sign.
• Case Sensitivity and Identifiers
  Sensitivity to the case (upper or lower) of identifiers and data depends on the sort order installed on your SAP ASE server.
• Uniqueness of Object Names
  Object names need not be unique in a database. However, column names and index names must be unique within a table, and other object names must be unique for each owner within a database. Database names must be unique on the SAP ASE server.
• Using Delimited Identifiers
  Delimited identifiers are object names enclosed in double quotes. Using delimited identifiers allows you to avoid certain restrictions on object names. In earlier versions of SAP ASE, only table, view, and column names could be delimited by quotes; other object names could not. This changed beginning with SAP ASE version 15.7, although enabling the ability requires setting a configuration parameter.
• Identifying Tables or Columns by Their Qualified Object Name
  You can uniquely identify a table or column by adding other names that qualify it—the database name, owner’s name, and (for a column) the table or view name.
• Determining Whether an Identifier is Valid
  Use the system function valid_name, after changing character sets or before creating a table or view, to determine whether the object name is acceptable to the SAP ASE server.
• Renaming Database Objects
  Rename user objects (including user-defined datatypes) with sp_rename.
• Using Multibyte Character Sets
  In multibyte character sets, a wider range of characters is available for use in identifiers. For example, on a server with the Japanese language installed, the following types of characters may be used as the first character of an identifier: Zenkaku or Hankaku Katakana, Hiragana, Kanji, Romaji, Greek, Cyrillic, or ASCII.