records and row types.
Pavel Stehule
<!--
-$PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.84 2006/02/05 02:47:53 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.85 2006/02/12 06:03:38 momjian Exp $
-->
<chapter id="plpgsql">
accordingly. The syntax is:
<synopsis>
<optional> <<<replaceable>label</replaceable>>> </optional>
-FOR <replaceable>record_or_row</replaceable> IN <replaceable>query</replaceable> LOOP
+FOR <replaceable>target</replaceable> IN <replaceable>query</replaceable> LOOP
<replaceable>statements</replaceable>
END LOOP <optional> <replaceable>label</replaceable> </optional>;
</synopsis>
- The record or row variable is successively assigned each row
+ <replaceable>Target</replaceable> is a record variable, row variable,
+ or a comma-separated list of simple variables and record/row fields
+ which is successively assigned each row
resulting from the <replaceable>query</replaceable> (which must be a
<command>SELECT</command> command) and the loop body is executed for each
row. Here is an example:
rows:
<synopsis>
<optional> <<<replaceable>label</replaceable>>> </optional>
-FOR <replaceable>record_or_row</replaceable> IN EXECUTE <replaceable>text_expression</replaceable> LOOP
+FOR <replaceable>target</replaceable> IN EXECUTE <replaceable>text_expression</replaceable> LOOP
<replaceable>statements</replaceable>
END LOOP <optional> <replaceable>label</replaceable> </optional>;
</synopsis>
<literal>IN</> and <literal>LOOP</>. If <literal>..</> is not seen then
the loop is presumed to be a loop over rows. Mistyping the <literal>..</>
is thus likely to lead to a complaint along the lines of
- <quote>loop variable of loop over rows must be a record or row variable</>,
+ <quote>loop variable of loop over rows must be a record or row or scalar variable</>,
rather than the simple syntax error one might expect to get.
</para>
</note>
* procedural language
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.83 2006/02/12 04:59:32 tgl Exp $
+ * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.84 2006/02/12 06:03:38 momjian Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
static void plpgsql_sql_error_callback(void *arg);
static void check_labels(const char *start_label,
const char *end_label);
-
+static PLpgSQL_row *make_scalar_list1(const char *name,
+ PLpgSQL_datum *variable);
+
%}
%union {
int lineno;
PLpgSQL_rec *rec;
PLpgSQL_row *row;
+ PLpgSQL_datum *scalar;
} forvariable;
struct
{
new->row = $2.row;
check_assignable((PLpgSQL_datum *) new->row);
}
+ else if ($2.scalar)
+ {
+ new->row = make_scalar_list1($2.name, $2.scalar);
+ check_assignable((PLpgSQL_datum *) new->row);
+ }
else
{
plpgsql_error_lineno = $1;
- yyerror("loop variable of loop over rows must be a record or row variable");
+ yyerror("loop variable of loop over rows must be a record, row, or scalar variable");
}
new->query = expr;
expr2 = plpgsql_read_expression(K_LOOP, "LOOP");
+ /* T_SCALAR identifier waits for converting */
+ if ($2.scalar)
+ {
+ char *name;
+ plpgsql_convert_ident($2.name, &name, 1);
+ pfree($2.name);
+ $2.name = name;
+ }
+
/* create loop's private variable */
fvar = (PLpgSQL_var *)
plpgsql_build_variable($2.name,
new->row = $2.row;
check_assignable((PLpgSQL_datum *) new->row);
}
+ else if ($2.scalar)
+ {
+ new->row = make_scalar_list1($2.name, $2.scalar);
+ check_assignable((PLpgSQL_datum *) new->row);
+ }
else
{
plpgsql_error_lineno = $1;
- yyerror("loop variable of loop over rows must be record or row variable");
+ yyerror("loop variable of loop over rows must be record, row, or scalar variable");
}
new->query = expr1;
* until we know what's what.
*/
for_variable : T_SCALAR
- {
+ {
+ int tok;
char *name;
+
+ name = pstrdup(yytext);
+ $$.scalar = yylval.scalar;
+ $$.lineno = plpgsql_scanner_lineno();
- plpgsql_convert_ident(yytext, &name, 1);
- $$.name = name;
- $$.lineno = plpgsql_scanner_lineno();
- $$.rec = NULL;
- $$.row = NULL;
+ if((tok = yylex()) == ',')
+ {
+ plpgsql_push_back_token(tok);
+ $$.name = NULL;
+ $$.row = read_into_scalar_list(name, $$.scalar);
+ $$.rec = NULL;
+ $$.scalar = NULL;
+
+ pfree(name);
+ }
+ else
+ {
+ plpgsql_push_back_token(tok);
+ $$.name = name;
+ $$.row = NULL;
+ $$.rec = NULL;
+ }
}
| T_WORD
{
}
| T_RECORD
{
- char *name;
-
- plpgsql_convert_ident(yytext, &name, 1);
- $$.name = name;
+ $$.name = NULL;
$$.lineno = plpgsql_scanner_lineno();
$$.rec = yylval.rec;
$$.row = NULL;
}
| T_ROW
{
- char *name;
-
- plpgsql_convert_ident(yytext, &name, 1);
- $$.name = name;
+ $$.name = NULL;
$$.lineno = plpgsql_scanner_lineno();
$$.row = yylval.row;
$$.rec = NULL;
}
+static PLpgSQL_row *
+make_scalar_list1(const char *name,
+ PLpgSQL_datum *variable)
+{
+ PLpgSQL_row *row;
+ check_assignable(variable);
+
+ row = palloc(sizeof(PLpgSQL_row));
+ row->dtype = PLPGSQL_DTYPE_ROW;
+ row->refname = pstrdup("*internal*");
+ row->lineno = plpgsql_scanner_lineno();
+ row->rowtupdesc = NULL;
+ row->nfields = 1;
+ row->fieldnames = palloc(sizeof(char *) * 1);
+ row->varnos = palloc(sizeof(int) * 1);
+ row->fieldnames[0] = pstrdup(name);
+ row->varnos[0] = variable->dno;
+
+ plpgsql_adddatum((PLpgSQL_datum *)row);
+
+ return row;
+}
+
+
static void
check_assignable(PLpgSQL_datum *datum)
{
$$ language plpgsql;
ERROR: end label "outer_label" specified for unlabelled block
CONTEXT: compile of PL/pgSQL function "end_label4" near line 5
+-- using list of scalars in fori and fore stmts
+create function for_vect() returns void as $$
+<<lbl>>declare a integer; b varchar; c varchar; r record;
+begin
+ -- old fori
+ for i in 1 .. 10 loop
+ raise notice '%', i;
+ end loop;
+ for a in select 1 from generate_series(1,4) loop
+ raise notice '%', a;
+ end loop;
+ for a,b,c in select generate_series, 'BB','CC' from generate_series(1,4) loop
+ raise notice '% % %', a, b, c;
+ end loop;
+ -- using qualified names in fors, fore is enabled, disabled only for fori
+ for lbl.a, lbl.b, lbl.c in execute E'select generate_series, \'bb\',\'cc\' from generate_series(1,4)' loop
+ raise notice '% % %', a, b, c;
+ end loop;
+end;
+$$ language plpgsql;
end loop outer_label;
end;
$$ language plpgsql;
+
+
+-- using list of scalars in fori and fore stmts
+create function for_vect() returns void as $$
+<<lbl>>declare a integer; b varchar; c varchar; r record;
+begin
+ -- old fori
+ for i in 1 .. 10 loop
+ raise notice '%', i;
+ end loop;
+ for a in select 1 from generate_series(1,4) loop
+ raise notice '%', a;
+ end loop;
+ for a,b,c in select generate_series, 'BB','CC' from generate_series(1,4) loop
+ raise notice '% % %', a, b, c;
+ end loop;
+ -- using qualified names in fors, fore is enabled, disabled only for fori
+ for lbl.a, lbl.b, lbl.c in execute E'select generate_series, \'bb\',\'cc\' from generate_series(1,4)' loop
+ raise notice '% % %', a, b, c;
+ end loop;
+end;
+$$ language plpgsql;
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