Geoff Winkless <> writes:
> I grabbed the wrong section of the doc; I should of course have pasted
> the searched version:

> <update statement: searched> ::=
>               UPDATE <table name>
>                 SET <set clause list>
>                 [ WHERE <search condition> ]

> My point is still the same though :)

Don't know which version of the SQL spec you're looking at, but SQL:2008

<update statement: searched> ::=
  UPDATE <target table> [ [ AS ] <correlation name> ]
      SET <set clause list>
      [ WHERE <search condition> ]

Note the [ [ AS ] <correlation name> ] bit.  However, they do NOT
allow the correlation name to appear in <set target>:

<set clause list> ::=
  <set clause> [ { <comma> <set clause> }... ]

<set clause> ::=
    <multiple column assignment>
  | <set target> <equals operator> <update source>

<set target> ::=
    <update target>
  | <mutated set clause>

<multiple column assignment> ::=
  <set target list> <equals operator> <assigned row>

<set target list> ::=
  <left paren> <set target> [ { <comma> <set target> }... ] <right paren>

<assigned row> ::=
  <contextually typed row value expression>

<update target> ::=
    <object column>
  | <object column>
      <left bracket or trigraph> <simple value specification> <right bracket or 

<object column> ::=
  <column name>

<mutated set clause> ::=
  <mutated target> <period> <method name>

<mutated target> ::=
    <object column>
  | <mutated set clause>

<update source> ::=
    <value expression>
  | <contextually typed value specification>

<column name> is elsewhere defined as just <identifier>, if you were
hoping there was more there than meets the eye.  The "mutated target"
business is some overly complex version of composite-type columns.

The reason why SQL doesn't allow an optional correlation name, and
probably never will, is the same as the reason why we don't, and probably
never will: it introduces an ambiguity as to whether you meant a dotted
set-clause target name to be a reference to a field of a composite column
or just a noise-word reference to the table's correlation name.  If there
were any functional value in specifying the correlation name, it might be
worth dealing with the ambiguity; but there isn't.

                        regards, tom lane

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