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From Apache Wiki <wikidi...@apache.org>
Subject [Db-derby Wiki] Update of "BuiltInLanguageBasedOrderingDERBY-1478" by DanDebrunner
Date Thu, 22 Mar 2007 14:49:42 GMT
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The following page has been changed by DanDebrunner:

  6)For a string literal which is not inside an operation like upper/lower/substring etc,
it's collation type in DTD will be marked UNKNOWN. When such a string literal gets used in
a collation method, it's collation type will be same as the other operand involved in the
collation eg sysColumn1 < 'aaa', then the collation type of 'aaa' will change from UNKNOWN
to UCS_LOCALE at the comparison time. But if the comparison was userColumn1 < 'aaa', then
the collation type of 'aaa' will be that of the collaiton type of userColumn1. As a third
case, if the comparison was between 2 string literals, ie 'aaa' < 'bbb', then the collation
type of each of the string literal will be the COLLATION applicable at the user character
+    '''Question''' Does this match the SQL standard?
  7)As for the character expressions involving CAST, TRIM, UPPER, LOWER, SUBSTRING, CONCATENATE,
the result character datatype will have the same collation type as their operands. 
+    '''Questions''' What about other character expressions, such as functions? What happens
when CONCATENATE is passed two values with different collations?
  8)When a character column is added using CREATE TABLE/ALTER TABLE, make sure that the correct
collate type is populated in the TypeDescriptor's scale field in the SYS.SYSCOLUMNS table.

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