'\" t
.\"     Title: CREATE COLLATION
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
.\"      Date: 2017-11-06
.\"    Manual: PostgreSQL 9.2.24 Documentation
.\"    Source: PostgreSQL 9.2.24
.\"  Language: English
.\"
.TH "CREATE COLLATION" "7" "2017-11-06" "PostgreSQL 9.2.24" "PostgreSQL 9.2.24 Documentation"
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.SH "NAME"
CREATE_COLLATION \- define a new collation
.\" CREATE COLLATION
.SH "SYNOPSIS"
.sp
.nf
CREATE COLLATION \fIname\fR (
    [ LOCALE = \fIlocale\fR, ]
    [ LC_COLLATE = \fIlc_collate\fR, ]
    [ LC_CTYPE = \fIlc_ctype\fR ]
)
CREATE COLLATION \fIname\fR FROM \fIexisting_collation\fR
.fi
.SH "DESCRIPTION"
.PP
\fBCREATE COLLATION\fR
defines a new collation using the specified operating system locale settings, or by copying an existing collation\&.
.PP
To be able to create a collation, you must have
CREATE
privilege on the destination schema\&.
.SH "PARAMETERS"
.PP
\fIname\fR
.RS 4
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\&.)
.RE
.PP
\fIlocale\fR
.RS 4
This is a shortcut for setting
LC_COLLATE
and
LC_CTYPE
at once\&. If you specify this, you cannot specify either of those parameters\&.
.RE
.PP
\fIlc_collate\fR
.RS 4
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 (\fBCREATE_DATABASE\fR(7))
for the precise rules\&.)
.RE
.PP
\fIlc_ctype\fR
.RS 4
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 (\fBCREATE_DATABASE\fR(7))
for the precise rules\&.)
.RE
.PP
\fIexisting_collation\fR
.RS 4
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\&.
.RE
.SH "NOTES"
.PP
Use
\fBDROP COLLATION\fR
to remove user\-defined collations\&.
.PP
See
Section 22.2, \(lqCollation Support\(rq, in the documentation
for more information about collation support in PostgreSQL\&.
.SH "EXAMPLES"
.PP
To create a collation from the operating system locale
fr_FR\&.utf8
(assuming the current database encoding is
UTF8):
.sp
.if n \{\
.RS 4
.\}
.nf
CREATE COLLATION french (LOCALE = \*(Aqfr_FR\&.utf8\*(Aq);
.fi
.if n \{\
.RE
.\}
.PP
To create a collation from an existing collation:
.sp
.if n \{\
.RS 4
.\}
.nf
CREATE COLLATION german FROM "de_DE";
.fi
.if n \{\
.RE
.\}
.sp
This can be convenient to be able to use operating\-system\-independent collation names in applications\&.
.SH "COMPATIBILITY"
.PP
There is a
\fBCREATE COLLATION\fR
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\&.
.SH "SEE ALSO"
ALTER COLLATION (\fBALTER_COLLATION\fR(7)), DROP COLLATION (\fBDROP_COLLATION\fR(7))
