CREATE COLLATION

`CREATE COLLATION`

Defines a new collation for a character set

Available in

DSQL

Syntax

CREATE COLLATION collname
    FOR charset
    [FROM {basecoll | EXTERNAL ('extname')}]
    [NO PAD | PAD SPACE]
    [CASE [IN]SENSITIVE]
    [ACCENT [IN]SENSITIVE]
    ['<specific-attributes>']

<specific-attributes> ::= <attribute> [; <attribute> ...]

<attribute> ::= attrname=attrvalue

Table 1. `CREATE COLLATION` Statement Parameters
Parameter	Description
collname	The name to use for the new collation.The maximum length is 63 characters
charset	A character set present in the database
basecoll	A collation already present in the database
extname	The collation name used in the `.conf` file

The CREATE COLLATION statement does not “create” anything, its purpose is to make a collation known to a database.The collation must already be present on the system, typically in a library file, and must be properly registered in a .conf file in the intl subdirectory of the Firebird installation.

The collation may alternatively be based on one that is already present in the database.

How the Engine Detects the Collation

The optional FROM clause specifies the base collation that is used to derive a new collation.This collation must already be present in the database.If the keyword EXTERNAL is specified, then Firebird will scan the .conf files in $fbroot/intl/, where extname must exactly match the name in the configuration file (case-sensitive).

If no FROM clause is present, Firebird will scan the .conf file(s) in the intl subdirectory for a collation with the collation name specified in CREATE COLLATION.In other words, omitting the FROM basecoll clause is equivalent to specifying FROM EXTERNAL ('collname').

The — single-quoted — extname is case-sensitive and must correspond exactly with the collation name in the .conf file.The collname, charset and basecoll parameters are case-insensitive unless enclosed in double-quotes.

When creating a collation, you can specify whether trailing spaces are included in the comparison.If the NO PAD clause is specified, trailing spaces are taken into account in the comparison.If the PAD SPACE clause is specified, trailing spaces are ignored in the comparison.

The optional CASE clause allows you to specify whether the comparison is case-sensitive or case-insensitive.

The optional ACCENT clause allows you to specify whether the comparison is accent-sensitive or accent-insensitive (e.g. if ‘'e'’ and ‘'é'’ are considered equal or unequal).