bk commit - mysqldoc tree (paul:1.2708)

[paul]

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ChangeSet
  1.2708 05/03/11 13:23:39 paul@stripped +1 -0
  manual.texi:
    Document change to COERCIBILITY() function.
    Document bugfix. (Bug #4291)

  Docs/manual.texi
    1.2538 05/03/11 13:21:59 paul@stripped +43 -11
    Document change to COERCIBILITY() function.
    Document bugfix. (Bug #4291)

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	paul
# Host:	frost.snake.net
# Root:	/Volumes/frost2/MySQL/bk/mysqldoc

--- 1.2537/Docs/manual.texi	2005-03-11 11:09:47 -06:00
+++ 1.2538/Docs/manual.texi	2005-03-11 13:21:59 -06:00
@@ -43420,10 +43420,17 @@
 
 @item A column's collation has a coercibility of 2.
 
-@item A literal's collation has a coercibility of 3.
+@item A ``system constant'' (the string returned by functions such as
+@code{USER()} or @code{VERSION()}) has a coercibility of 3.
+
+@item A literal's collation has a coercibility of 4.
 
 @end itemize
 
+The preceding coercibility values are current as of MySQL 4.1.11 and 5.0.3.
+See the note later in this section for additional version-related
+information.
+
 Those rules resolve ambiguities thus:
 
 @itemize @bullet
@@ -43451,12 +43458,18 @@
 @example
 mysql> SELECT COERCIBILITY('A' COLLATE latin1_swedish_ci);
         -> 0
-mysql> SELECT COERCIBILITY('A');
+mysql> SELECT COERCIBILITY(VERSION());
         -> 3
+mysql> SELECT COERCIBILITY('A');
+        -> 4
 @end example
 
 @xref{Information functions}.
 
+Before MySQL 4.1.11 and 5.0.3, there is no system constant coercibility.
+Functions such as @code{USER()} have a coercibility of 2 rather than 3, and
+literals have a coercibility of 3 rather than 4.
+
 
 @node Charset-collation-charset, Charset-collation-effect, Charset-collate-tricky, Charset-defaults
 @subsection Collations Must Be for the Right Character Set
@@ -52407,24 +52420,28 @@
 mysql> SELECT COERCIBILITY('abc' COLLATE latin1_swedish_ci);
         -> 0
 mysql> SELECT COERCIBILITY('abc');
-        -> 3
+        -> 4
 mysql> SELECT COERCIBILITY(USER());
-        -> 2
+        -> 3
 @end example
 
 The return values have the following meanings:
 
-@multitable @columnfractions .30 .50
-@item @strong{Coercibility} @tab @strong{Meaning}
-@item @code{0} @tab Explicit collation
-@item @code{1} @tab No collation
-@item @code{2} @tab Implicit collation
-@item @code{3} @tab Coercible
+@multitable @columnfractions .15 .15 .70
+@item @strong{Coercibility} @tab @strong{Meaning} @tab @strong{Example}
+@item @code{0} @tab Explicit collation @tab Value with @code{COLLATE} clause
+@item @code{1} @tab No collation @tab Concatenation of strings with different collations
+@item @code{2} @tab Implicit collation @tab Column value
+@item @code{3} @tab System constant @tab @code{USER()} return value
+@item @code{4} @tab Coercible @tab Literal string
 @end multitable
 
 Lower values have higher precedence.
 
-@code{COERCIBILITY()} was added in MySQL 4.1.1.
+@code{COERCIBILITY()} was added in MySQL 4.1.1.  Before MYSQL 4.1.11 and
+5.0.3, the system constant coercibility value is not present: Functions such
+as @code{USER()} have a coercibility of 2, and literal strings have a
+coercibility of 3 rather than 4.
 
 @c description_for_help_topic COLLATION
 @findex COLLATION()
@@ -97019,6 +97036,13 @@
 (Thanks to Stefano Di Paola @email{stefano.dipaola@@wisec.it} for finding
 and informing us about this issue.)
 @item
+The coercibility for the return value of functions such as @code{USER()} or
+@code{VERSION()} now is ``system constant'' rather than ``implicit.''  This
+makes these functions more coercible than column values so that comparisons
+of the two do not result in @code{Illegal mix of collations} errors.
+@code{COERCIBILITY()} was modified to accommodate this new coercibility value.
+@xref{Information functions}.
+@item
 Boolean full-text phrase searching now requires only that matches contain
 exactly the same words as the phrase and in the same order. Non-word
 characters no longer need match exactly.
@@ -98185,6 +98209,14 @@
 
 Functionality added or changed:
 @itemize @bullet
+@item
+The coercibility for the return value of functions such as @code{USER()} or
+@code{VERSION()} now is ``system constant'' rather than ``implicit.''  This
+makes these functions more coercible than column values so that comparisons
+of the two do not result in @code{Illegal mix of collations} errors.
+@code{COERCIBILITY()} was modified to accommodate this new coercibility value.
+@xref{Information functions}.
+value.
 @item
 Modified the parser to allow @code{SELECT} statements following the
 @code{UNION} keyword to be subqueries in parentheses. (Bug #2435)