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Support EXECUTE USING in plpgsql.

Browse Source 
Pavel Stehule, with some improvements by myself.
This commit is contained in:
Tom Lane
2008-04-01 03:51:09 +00:00
parent d5466e38f0
commit e2a8804330
8 changed files with 350 additions and 60 deletions
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115
src/pl/plpgsql/src/gram.y
View File

@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.108 2008/01/01 19:46:00 momjian Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.109 2008/04/01 03:51:09 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -21,11 +21,15 @@
static PLpgSQL_expr *read_sql_construct(int until,
int until2,
int until3,
const char *expected,
const char *sqlstart,
bool isexpression,
bool valid_sql,
int *endtoken);
static PLpgSQL_expr *read_sql_expression2(int until, int until2,
const char *expected,
int *endtoken);
static PLpgSQL_expr *read_sql_stmt(const char *sqlstart);
static PLpgSQL_type *read_datatype(int tok);
static PLpgSQL_stmt *make_execsql_stmt(const char *sqlstart, int lineno);
@ -200,6 +204,7 @@ static void check_labels(const char *start_label,
%token K_THEN
%token K_TO
%token K_TYPE
%token K_USING
%token K_WARNING
%token K_WHEN
%token K_WHILE
@ -892,8 +897,11 @@ for_control :
{
PLpgSQL_stmt_dynfors *new;
PLpgSQL_expr *expr;
int term;
expr = plpgsql_read_expression(K_LOOP, "LOOP");
expr = read_sql_expression2(K_LOOP, K_USING,
"LOOP or USING",
&term);
new = palloc0(sizeof(PLpgSQL_stmt_dynfors));
new->cmd_type = PLPGSQL_STMT_DYNFORS;
@ -921,6 +929,17 @@ for_control :
}
new->query = expr;
if (term == K_USING)
{
do
{
expr = read_sql_expression2(',', K_LOOP,
", or LOOP",
&term);
new->params = lappend(new->params, expr);
} while (term == ',');
}
$$ = (PLpgSQL_stmt *) new;
}
else
@ -954,6 +973,7 @@ for_control :
*/
expr1 = read_sql_construct(K_DOTDOT,
K_LOOP,
0,
"LOOP",
"SELECT ",
true,
@ -973,17 +993,14 @@ for_control :
check_sql_expr(expr1->query);
/* Read and check the second one */
expr2 = read_sql_construct(K_LOOP,
K_BY,
"LOOP",
"SELECT ",
true,
true,
&tok);
expr2 = read_sql_expression2(K_LOOP, K_BY,
"LOOP",
&tok);
/* Get the BY clause if any */
if (tok == K_BY)
expr_by = plpgsql_read_expression(K_LOOP, "LOOP");
expr_by = plpgsql_read_expression(K_LOOP,
"LOOP");
else
expr_by = NULL;
@ -1217,18 +1234,15 @@ stmt_raise : K_RAISE lno raise_level raise_msg
if (tok == ',')
{
PLpgSQL_expr *expr;
int term;
for (;;)
do
{
expr = read_sql_construct(',', ';', ", or ;",
"SELECT ",
true, true, &term);
PLpgSQL_expr *expr;
expr = read_sql_expression2(',', ';',
", or ;",
&tok);
new->params = lappend(new->params, expr);
if (term == ';')
break;
}
} while (tok == ',');
}
$$ = (PLpgSQL_stmt *)new;
@ -1307,7 +1321,8 @@ stmt_dynexecute : K_EXECUTE lno
PLpgSQL_expr *expr;
int endtoken;
expr = read_sql_construct(K_INTO, ';', "INTO|;",
expr = read_sql_construct(K_INTO, K_USING, ';',
"INTO or USING or ;",
"SELECT ",
true, true, &endtoken);
@ -1319,16 +1334,30 @@ stmt_dynexecute : K_EXECUTE lno
new->strict = false;
new->rec = NULL;
new->row = NULL;
new->params = NIL;
/* If we found "INTO", collect the argument */
if (endtoken == K_INTO)
{
new->into = true;
read_into_target(&new->rec, &new->row, &new->strict);
if (yylex() != ';')
endtoken = yylex();
if (endtoken != ';' && endtoken != K_USING)
yyerror("syntax error");
}
/* If we found "USING", collect the argument(s) */
if (endtoken == K_USING)
{
do
{
expr = read_sql_expression2(',', ';',
", or ;",
&endtoken);
new->params = lappend(new->params, expr);
} while (endtoken == ',');
}
$$ = (PLpgSQL_stmt *)new;
}
;
@ -1485,7 +1514,7 @@ stmt_fetch : K_FETCH lno opt_fetch_direction cursor_variable K_INTO
$$ = (PLpgSQL_stmt *)fetch;
}
;
stmt_move : K_MOVE lno opt_fetch_direction cursor_variable ';'
{
PLpgSQL_stmt_fetch *fetch = $3;
@ -1730,16 +1759,29 @@ assign_expr_param(int dno, int *params, int *nparams)
}
/* Convenience routine to read an expression with one possible terminator */
PLpgSQL_expr *
plpgsql_read_expression(int until, const char *expected)
{
return read_sql_construct(until, 0, expected, "SELECT ", true, true, NULL);
return read_sql_construct(until, 0, 0, expected,
"SELECT ", true, true, NULL);
}
/* Convenience routine to read an expression with two possible terminators */
static PLpgSQL_expr *
read_sql_expression2(int until, int until2, const char *expected,
int *endtoken)
{
return read_sql_construct(until, until2, 0, expected,
"SELECT ", true, true, endtoken);
}
/* Convenience routine to read a SQL statement that must end with ';' */
static PLpgSQL_expr *
read_sql_stmt(const char *sqlstart)
{
return read_sql_construct(';', 0, ";", sqlstart, false, true, NULL);
return read_sql_construct(';', 0, 0, ";",
sqlstart, false, true, NULL);
}
/*
@ -1747,16 +1789,18 @@ read_sql_stmt(const char *sqlstart)
*
* until: token code for expected terminator
* until2: token code for alternate terminator (pass 0 if none)
* until3: token code for another alternate terminator (pass 0 if none)
* expected: text to use in complaining that terminator was not found
* sqlstart: text to prefix to the accumulated SQL text
* isexpression: whether to say we're reading an "expression" or a "statement"
* valid_sql: whether to check the syntax of the expr (prefixed with sqlstart)
* endtoken: if not NULL, ending token is stored at *endtoken
* (this is only interesting if until2 isn't zero)
* (this is only interesting if until2 or until3 isn't zero)
*/
static PLpgSQL_expr *
read_sql_construct(int until,
int until2,
int until3,
const char *expected,
const char *sqlstart,
bool isexpression,
@ -1783,6 +1827,8 @@ read_sql_construct(int until,
break;
if (tok == until2 && parenlevel == 0)
break;
if (tok == until3 && parenlevel == 0)
break;
if (tok == '(' || tok == '[')
parenlevel++;
else if (tok == ')' || tok == ']')
@ -2066,15 +2112,17 @@ read_fetch_direction(void)
else if (pg_strcasecmp(yytext, "absolute") == 0)
{
fetch->direction = FETCH_ABSOLUTE;
fetch->expr = read_sql_construct(K_FROM, K_IN, "FROM or IN",
"SELECT ", true, true, NULL);
fetch->expr = read_sql_expression2(K_FROM, K_IN,
"FROM or IN",
NULL);
check_FROM = false;
}
else if (pg_strcasecmp(yytext, "relative") == 0)
{
fetch->direction = FETCH_RELATIVE;
fetch->expr = read_sql_construct(K_FROM, K_IN, "FROM or IN",
"SELECT ", true, true, NULL);
fetch->expr = read_sql_expression2(K_FROM, K_IN,
"FROM or IN",
NULL);
check_FROM = false;
}
else if (pg_strcasecmp(yytext, "forward") == 0)
@ -2088,8 +2136,9 @@ read_fetch_direction(void)
else if (tok != T_SCALAR)
{
plpgsql_push_back_token(tok);
fetch->expr = read_sql_construct(K_FROM, K_IN, "FROM or IN",
"SELECT ", true, true, NULL);
fetch->expr = read_sql_expression2(K_FROM, K_IN,
"FROM or IN",
NULL);
check_FROM = false;
}
else
@ -2233,7 +2282,7 @@ make_return_query_stmt(int lineno)
new = palloc0(sizeof(PLpgSQL_stmt_return_query));
new->cmd_type = PLPGSQL_STMT_RETURN_QUERY;
new->lineno = lineno;
new->query = read_sql_construct(';', 0, ")", "", false, true, NULL);
new->query = read_sql_stmt("");
return (PLpgSQL_stmt *) new;
}

139
src/pl/plpgsql/src/pl_exec.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.207 2008/03/28 00:21:56 tgl Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.208 2008/04/01 03:51:09 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -38,6 +38,15 @@
static const char *const raise_skip_msg = "RAISE";
typedef struct
{
int nargs; /* number of arguments */
Oid *types; /* types of arguments */
Datum *values; /* evaluated argument values */
char *nulls; /* null markers (' '/'n' style) */
bool *freevals; /* which arguments are pfree-able */
} PreparedParamsData;
/*
* All plpgsql function executions within a single transaction share the same
* executor EState for evaluating "simple" expressions. Each function call
@ -178,6 +187,9 @@ static bool compatible_tupdesc(TupleDesc td1, TupleDesc td2);
static void exec_set_found(PLpgSQL_execstate *estate, bool state);
static void plpgsql_create_econtext(PLpgSQL_execstate *estate);
static void free_var(PLpgSQL_var *var);
static PreparedParamsData *exec_eval_using_params(PLpgSQL_execstate *estate,
List *params);
static void free_params_data(PreparedParamsData *ppd);
/* ----------
@ -2676,9 +2688,21 @@ exec_stmt_dynexecute(PLpgSQL_execstate *estate,
exec_eval_cleanup(estate);
/*
* Call SPI_execute() without preparing a saved plan.
* Execute the query without preparing a saved plan.
*/
exec_res = SPI_execute(querystr, estate->readonly_func, 0);
if (stmt->params)
{
PreparedParamsData *ppd;
ppd = exec_eval_using_params(estate, stmt->params);
exec_res = SPI_execute_with_args(querystr,
ppd->nargs, ppd->types,
ppd->values, ppd->nulls,
estate->readonly_func, 0);
free_params_data(ppd);
}
else
exec_res = SPI_execute(querystr, estate->readonly_func, 0);
switch (exec_res)
{
@ -2826,7 +2850,6 @@ exec_stmt_dynfors(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynfors *stmt)
PLpgSQL_row *row = NULL;
SPITupleTable *tuptab;
int n;
SPIPlanPtr plan;
Portal portal;
bool found = false;
@ -2856,19 +2879,35 @@ exec_stmt_dynfors(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynfors *stmt)
exec_eval_cleanup(estate);
/*
* Prepare a plan and open an implicit cursor for the query
* Open an implicit cursor for the query. We use SPI_cursor_open_with_args
* even when there are no params, because this avoids making and freeing
* one copy of the plan.
*/
plan = SPI_prepare(querystr, 0, NULL);
if (plan == NULL)
elog(ERROR, "SPI_prepare failed for \"%s\": %s",
querystr, SPI_result_code_string(SPI_result));
portal = SPI_cursor_open(NULL, plan, NULL, NULL,
estate->readonly_func);
if (stmt->params)
{
PreparedParamsData *ppd;
ppd = exec_eval_using_params(estate, stmt->params);
portal = SPI_cursor_open_with_args(NULL,
querystr,
ppd->nargs, ppd->types,
ppd->values, ppd->nulls,
estate->readonly_func, 0);
free_params_data(ppd);
}
else
{
portal = SPI_cursor_open_with_args(NULL,
querystr,
0, NULL,
NULL, NULL,
estate->readonly_func, 0);
}
if (portal == NULL)
elog(ERROR, "could not open implicit cursor for query \"%s\": %s",
querystr, SPI_result_code_string(SPI_result));
pfree(querystr);
SPI_freeplan(plan);
/*
* Fetch the initial 10 tuples
@ -5069,3 +5108,79 @@ free_var(PLpgSQL_var *var)
var->freeval = false;
}
}
/*
* exec_eval_using_params --- evaluate params of USING clause
*/
static PreparedParamsData *
exec_eval_using_params(PLpgSQL_execstate *estate, List *params)
{
PreparedParamsData *ppd;
int nargs;
int i;
ListCell *lc;
ppd = (PreparedParamsData *) palloc(sizeof(PreparedParamsData));
nargs = list_length(params);
ppd->nargs = nargs;
ppd->types = (Oid *) palloc(nargs * sizeof(Oid));
ppd->values = (Datum *) palloc(nargs * sizeof(Datum));
ppd->nulls = (char *) palloc(nargs * sizeof(char));
ppd->freevals = (bool *) palloc(nargs * sizeof(bool));
i = 0;
foreach(lc, params)
{
PLpgSQL_expr *param = (PLpgSQL_expr *) lfirst(lc);
bool isnull;
ppd->values[i] = exec_eval_expr(estate, param,
&isnull,
&ppd->types[i]);
ppd->nulls[i] = isnull ? 'n' : ' ';
ppd->freevals[i] = false;
/* pass-by-ref non null values must be copied into plpgsql context */
if (!isnull)
{
int16 typLen;
bool typByVal;
get_typlenbyval(ppd->types[i], &typLen, &typByVal);
if (!typByVal)
{
ppd->values[i] = datumCopy(ppd->values[i], typByVal, typLen);
ppd->freevals[i] = true;
}
}
exec_eval_cleanup(estate);
i++;
}
return ppd;
}
/*
* free_params_data --- pfree all pass-by-reference values used in USING clause
*/
static void
free_params_data(PreparedParamsData *ppd)
{
int i;
for (i = 0; i < ppd->nargs; i++)
{
if (ppd->freevals[i])
pfree(DatumGetPointer(ppd->values[i]));
}
pfree(ppd->types);
pfree(ppd->values);
pfree(ppd->nulls);
pfree(ppd->freevals);
pfree(ppd);
}

42
src/pl/plpgsql/src/pl_funcs.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.67 2008/01/01 19:46:00 momjian Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.68 2008/04/01 03:51:09 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1007,6 +1007,24 @@ dump_dynexecute(PLpgSQL_stmt_dynexecute *stmt)
stmt->strict ? " STRICT" : "",
stmt->row->rowno, stmt->row->refname);
}
if (stmt->params != NIL)
{
ListCell *lc;
int i;
dump_ind();
printf(" USING\n");
dump_indent += 2;
i = 1;
foreach(lc, stmt->params)
{
dump_ind();
printf(" parameter %d: ", i++);
dump_expr((PLpgSQL_expr *) lfirst(lc));
printf("\n");
}
dump_indent -= 2;
}
dump_indent -= 2;
}
@ -1014,12 +1032,30 @@ static void
dump_dynfors(PLpgSQL_stmt_dynfors *stmt)
{
dump_ind();
printf("FORS %s EXECUTE ", (stmt->rec != NULL) ? stmt->rec->refname : stmt->row->refname);
printf("FORS %s EXECUTE ",
(stmt->rec != NULL) ? stmt->rec->refname : stmt->row->refname);
dump_expr(stmt->query);
printf("\n");
if (stmt->params != NIL)
{
ListCell *lc;
int i;
dump_indent += 2;
dump_ind();
printf(" USING\n");
dump_indent += 2;
i = 1;
foreach(lc, stmt->params)
{
dump_ind();
printf(" parameter $%d: ", i++);
dump_expr((PLpgSQL_expr *) lfirst(lc));
printf("\n");
}
dump_indent -= 4;
}
dump_stmts(stmt->body);
dump_ind();
printf(" ENDFORS\n");
}

4
src/pl/plpgsql/src/plpgsql.h
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.95 2008/01/01 19:46:00 momjian Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.96 2008/04/01 03:51:09 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -430,6 +430,7 @@ typedef struct
PLpgSQL_row *row;
PLpgSQL_expr *query;
List *body; /* List of statements */
List *params; /* USING expressions */
} PLpgSQL_stmt_dynfors;
@ -534,6 +535,7 @@ typedef struct
bool strict; /* INTO STRICT flag */
PLpgSQL_rec *rec; /* INTO target, if record */
PLpgSQL_row *row; /* INTO target, if row */
List *params; /* USING expressions */
} PLpgSQL_stmt_dynexecute;

7
src/pl/plpgsql/src/scan.l
View File

@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.60 2008/01/01 19:46:00 momjian Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.61 2008/04/01 03:51:09 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -161,6 +161,7 @@ strict { return K_STRICT; }
then { return K_THEN; }
to { return K_TO; }
type { return K_TYPE; }
using { return K_USING; }
warning { return K_WARNING; }
when { return K_WHEN; }
while { return K_WHILE; }
@ -328,7 +329,7 @@ dump { return O_DUMP; }
}
<IN_DOLLARQUOTE>{dolqinside} { }
<IN_DOLLARQUOTE>. { /* needed for $ inside the quoted text */ }
<IN_DOLLARQUOTE><<EOF>> {
<IN_DOLLARQUOTE><<EOF>> {
plpgsql_error_lineno = start_lineno;
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
@ -502,7 +503,7 @@ plpgsql_scanner_finish(void)
* scenarios there's no need to get the decoded value.)
*
* Note: we expect the literal to be the most recently lexed token. This
* would not work well if we supported multiple-token pushback or if
* would not work well if we supported multiple-token pushback or if
* plpgsql_yylex() wanted to read ahead beyond a T_STRING token.
*/
char *

23
src/test/regress/expected/plpgsql.out
View File

@ -3128,3 +3128,26 @@ select * from ret_query2(8);
c9f0f895fb98ab9159f51fd0297e236d | 8 | t
(9 rows)
-- test EXECUTE USING
create function exc_using(int, text) returns int as $$
declare i int;
begin
for i in execute 'select * from generate_series(1,$1)' using $1+1 loop
raise notice '%', i;
end loop;
execute 'select $2 + $2*3 + length($1)' into i using $2,$1;
return i;
end
$$ language plpgsql;
select exc_using(5, 'foobar');
NOTICE: 1
NOTICE: 2
NOTICE: 3
NOTICE: 4
NOTICE: 5
NOTICE: 6
exc_using
-----------
26
(1 row)

16
src/test/regress/sql/plpgsql.sql
View File

@ -2580,4 +2580,18 @@ begin
end;
$$ language plpgsql;
select * from ret_query2(8);
select * from ret_query2(8);
-- test EXECUTE USING
create function exc_using(int, text) returns int as $$
declare i int;
begin
for i in execute 'select * from generate_series(1,$1)' using $1+1 loop
raise notice '%', i;
end loop;
execute 'select $2 + $2*3 + length($1)' into i using $2,$1;
return i;
end
$$ language plpgsql;
select exc_using(5, 'foobar');