Sybase 12.4.2 Sorting characters using collations, International aspects of case sensitivity, 322

Understanding character sets in software

Sorting characters using collations

Associating more than one character with each sort position

The database collation sequence includes the notion of alphabetic ordering of letters, and extends it to include all characters in the character set, including digits and space characters.

More than one character can be associated with each sort position. This is useful if you wish, for example, to treat an accented character the same as the character without an accent.

Two characters with the same sort position are considered identical in all ways by the database. Therefore, if a collation assigned the characters a and e to the same sort position, then a query with the following search condition:

WHERE col1 = ’want’

is satisfied by a row for which col1 contains the entry went.

At each sort position, lower- and uppercase forms of a character can be indicated. For case-sensitive databases (the default for IQ databases created as of version 12.4.2), the lower- and uppercase characters are not treated as equivalent. For case-insensitive databases, the lower- and uppercase versions of the character are considered equivalent.

First-byte collation orderings for multibyte character sets

A sorting order for characters in a multibyte character set can be specified only for the first byte. Characters that have the same first byte are sorted according to the hexadecimal value of the following bytes.

International aspects of case sensitivity

Adaptive Server IQ is case preserving and case insensitive for identifiers, such as table names and column names. This means that the names are stored in the case in which they are created, but any access to the identifiers is done in a case-insensitive manner.

For example, the names of the system tables are held in upper case (SYSDOMAIN, SYSTABLE, and so on), but access is case insensitive, so that the two following statements are equivalent:

SELECT *

FROM systable

SELECT *

FROM SYSTABLE

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