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1 | 1 | <!-- |
2 | | -$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.26 2000/12/1422:30:56 petere Exp $ |
| 2 | +$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.27 2000/12/16 18:22:53 tgl Exp $ |
3 | 3 | --> |
4 | 4 |
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5 | 5 | <chapter id="syntax"> |
@@ -791,24 +791,21 @@ sqrt(emp.salary) |
791 | 791 |
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792 | 792 | <para> |
793 | 793 | A <firstterm>target list</firstterm> |
794 | | - is aparenthesized,comma-separated list of one or more elements, each |
| 794 | + is a comma-separated list of one or more elements, each |
795 | 795 | of which must be of the form: |
796 | 796 |
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797 | 797 | <synopsis> |
798 | 798 | <replaceable>a_expr</replaceable> [ AS <replaceable>result_attname</replaceable> ] |
799 | 799 | </synopsis> |
800 | 800 |
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801 | 801 | where <replaceable>result_attname</replaceable> |
802 | | - is the name of the attribute to be created (or an |
803 | | - already existing attribute name in the case of update statements.) If |
| 802 | + is the name to be assigned to the created column. If |
804 | 803 | <replaceable>result_attname</replaceable> |
805 | | - is not present, then |
806 | | - <replaceable>a_expr</replaceable> |
807 | | - must contain only one attribute name which is assumed to be the name |
808 | | - of the result field. In <productname>Postgres</productname> |
809 | | - default naming is only used if |
810 | | - <replaceable>a_expr</replaceable> |
811 | | - is an attribute. |
| 804 | + is not present, then <productname>Postgres</productname> selects a |
| 805 | + default name based on the contents of <replaceable>a_expr</replaceable>. |
| 806 | + If <replaceable>a_expr</replaceable> is a simple attribute reference |
| 807 | + then the default name will be the same as that attribute's name, but |
| 808 | + otherwise the implementation is free to assign any default name. |
812 | 809 | </para> |
813 | 810 | </sect2> |
814 | 811 |
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