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Overview
Comment:Fix a recently introduced error regarding collation sequences and compounds SELECT statements.
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SHA1: 8d9fe20890d6948892550c513f1c2be3bbb09da0
User & Date: dan 2010-09-14 18:57:40.000
Context
2010-09-14
19:10
Adding additional comparison operators to the list in datatype3.html. (check-in: a43ee1e871 user: drh tags: trunk)
18:57
Fix a recently introduced error regarding collation sequences and compounds SELECT statements. (check-in: 8d9fe20890 user: dan tags: trunk)
13:25
Add <> to the list of comparison operators in datatype3.html. (check-in: 838bd2b455 user: drh tags: trunk)
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right SELECTs.  ^The EXCEPT operator returns the subset of rows returned by the
left SELECT that are not also returned by the right-hand SELECT. ^Duplicate
rows are removed from the results of INTERSECT and EXCEPT operators before the
result set is returned.

<p>^For the purposes of determining duplicate rows for the results of compound
SELECT operators, NULL values are considered equal to other NULL values and
distinct from all non-NULL values. ^The collation sequences to compare text
values values are determined as if the columns of the left and right-hand
distinct from all non-NULL values. ^The collation sequence used to compare 
two text values is determined as if the columns of the left and right-hand
SELECT statements were the left and right-hand operands of the equals (=)
operator, except that greater precedence is not assigned to a collation 
sequence specified with the postfix COLLATE operator. ^No affinity
operator. ^No affinity transformations are applied to any values when 
comparing rows as part of a compound SELECT. 
transformations are applied to any values when comparing rows as part of a
compound SELECT. 

<p>^(When three or more simple SELECTs are connected into a compound SELECT,
they group from left to right. In other words, if "A", "B" and "C" are all
simple SELECT statements, (A op B op C) is processed as ((A op B) op C).)^

</p>