The COLLATE operator determines the collation for an expression. This operator enables you to override the collation that the database would have derived for the expression using standard collation derivation rules.

COLLATE is a postfix unary operator. It has the same precedence as other unary operators, but it is evaluated after all prefix unary operators have been evaluated.

You can apply this operator to expressions of type VARCHAR2, CHAR, LONG, NVARCHAR, or NCHAR.

The COLLATE operator takes one argument, collation_name, for which you can specify a named collation or pseudo-collation. If the collation name contains a space, then you must enclose the name in double quotation marks.

Table 4-3 describes the COLLATE operator.

SELECT last_name
  FROM employees
  ORDER BY last_name COLLATE GENERIC_M;