NAME

       CREATE_COLLATION - define a new collation

SYNOPSIS

       CREATE COLLATION name (
           [ LOCALE = locale, ]
           [ LC_COLLATE = lc_collate, ]
           [ LC_CTYPE = lc_ctype ]
       )
       CREATE COLLATION name FROM existing_collation

DESCRIPTION

       CREATE COLLATION defines a new collation using the specified operating system locale settings, or by
       copying an existing collation.

       To be able to create a collation, you must have CREATE privilege on the destination schema.

PARAMETERS

       name
           The name of the collation. The collation name can be schema-qualified. If it is not, the collation is
           defined in the current schema. The collation name must be unique within that schema. (The system
           catalogs can contain collations with the same name for other encodings, but these are ignored if the
           database encoding does not match.)

       locale
           This is a shortcut for setting LC_COLLATE and LC_CTYPE at once. If you specify this, you cannot
           specify either of those parameters.

       lc_collate
           Use the specified operating system locale for the LC_COLLATE locale category. The locale must be
           applicable to the current database encoding. (See CREATE DATABASE (CREATE_DATABASE(7)) for the
           precise rules.)

       lc_ctype
           Use the specified operating system locale for the LC_CTYPE locale category. The locale must be
           applicable to the current database encoding. (See CREATE DATABASE (CREATE_DATABASE(7)) for the
           precise rules.)

       existing_collation
           The name of an existing collation to copy. The new collation will have the same properties as the
           existing one, but it will be an independent object.

NOTES

       Use DROP COLLATION to remove user-defined collations.

       See Section 22.2, “Collation Support”, in the documentation for more information about collation support
       in PostgreSQL.

EXAMPLES

       To create a collation from the operating system locale fr_FR.utf8 (assuming the current database encoding
       is UTF8):

           CREATE COLLATION french (LOCALE = 'fr_FR.utf8');

       To create a collation from an existing collation:

           CREATE COLLATION german FROM "de_DE";

       This can be convenient to be able to use operating-system-independent collation names in applications.

COMPATIBILITY

       There is a CREATE COLLATION statement in the SQL standard, but it is limited to copying an existing
       collation. The syntax to create a new collation is a PostgreSQL extension.

SEE ALSO

       ALTER COLLATION (ALTER_COLLATION(7)), DROP COLLATION (DROP_COLLATION(7))

PostgreSQL 9.5.25                                     2021                                   CREATE COLLATION(7)