Using ecpg with postgresql, unable to parse boolean field - postgresql

Question

I am trying to retrieve records from a PostgreSQL
I use the following script to create the database, table and fill it up with some records:
psql << "EOF"
CREATE DATABASE todo;
\c todo
CREATE TABLE items
(
id serial PRIMARY KEY,
task VARCHAR(40) NOT NULL,
complete boolean
);
INSERT INTO items (id, task, complete) VALUES (1, 'task1', true);
INSERT INTO items (id, task, complete) VALUES (2, 'task2', true);
INSERT INTO items (id, task, complete) VALUES (3, 'task3', true);
INSERT INTO items (id, task, complete) VALUES (4, 'task4', true);
INSERT INTO items (id, task, complete) VALUES (5, 'task5', false);
INSERT INTO items (id, task, complete) VALUES (6, 'task6', false);
EOF
I use a) structure as well as b) individual variables to handle the problem. Method a) could not parse boolean field complete. Here is the program:
#include <stdio.h>
#include <stdlib.h>
#include <ecpglib.h>
int
main(void)
{
#if ENABLE_DEBUG
ECPGdebug(1, stderr);
#endif
EXEC SQL WHENEVER SQLERROR sqlprint;
EXEC SQL BEGIN DECLARE SECTION;
/* Use structure as host variable */
typedef struct {
int id;
char task[40];
bool complete;
} item_t;
item_t item;
/* Use individual variables as host variables */
int id;
char task[40];
bool complete;
EXEC SQL END DECLARE SECTION;
memset(&item, 0, sizeof(item_t));
EXEC SQL CONNECT TO todo;
/*
* Use structure as host variable
*/
EXEC SQL DECLARE cur1 CURSOR FOR
SELECT id, task, complete
FROM items;
EXEC SQL OPEN cur1;
printf("sizeof(item_t) = %ld\n", sizeof(item));
printf(" sizeof(item.int) = %ld\n", sizeof(item.id));
printf(" sizeof(item.task) = %ld\n", sizeof(item.task));
printf(" sizeof(item.complete) = %ld\n", sizeof(item.complete));
printf("\n"
"Using structure variable\n"
"------------------------\n");
EXEC SQL WHENEVER NOT FOUND DO BREAK;
while (1)
{
EXEC SQL FETCH FROM cur1 INTO :item;
printf("id=%d, task=%s, complete=%d\n\n",
item.id, item.task, item.complete);
}
EXEC SQL CLOSE cur1;
/*
* Use individual variables as host variables
*/
EXEC SQL DECLARE cur2 CURSOR FOR
SELECT id, task, complete
FROM items;
EXEC SQL OPEN cur2;
printf("sizeof(int) = %ld\n", sizeof(id));
printf("sizeof(task) = %ld\n", sizeof(task));
printf("sizeof(complete) = %ld\n", sizeof(complete));
printf("\n"
"Using individual variables\n"
"--------------------------\n");
EXEC SQL WHENEVER NOT FOUND DO BREAK;
while (1)
{
EXEC SQL FETCH FROM cur2 INTO :id, :task, :complete;
printf("id=%d, task=%s, complete=%d\n",
id, task, complete);
}
EXEC SQL CLOSE cur2;
EXEC SQL DISCONNECT ALL;
return 0;
}
The outputs:
sizeof(item_t) = 48
sizeof(item.int) = 4
sizeof(item.task) = 40
sizeof(item.complete) = 1
Using structure variable
------------------------
SQL error: could not convert boolean value: size mismatch, on line 80
id=1, task=task1, complete=0
SQL error: could not convert boolean value: size mismatch, on line 80
id=2, task=task2, complete=0
SQL error: could not convert boolean value: size mismatch, on line 80
id=3, task=task3, complete=0
SQL error: could not convert boolean value: size mismatch, on line 80
id=4, task=task4, complete=0
SQL error: could not convert boolean value: size mismatch, on line 80
id=5, task=task5, complete=0
SQL error: could not convert boolean value: size mismatch, on line 80
id=6, task=task6, complete=0
sizeof(int) = 4
sizeof(task) = 40
sizeof(complete) = 1
Using individual variables
--------------------------
id=1, task=task1, complete=1
id=2, task=task2, complete=1
id=3, task=task3, complete=1
id=4, task=task4, complete=1
id=5, task=task5, complete=0
id=6, task=task6, complete=0

Answer 1

The problem was raised as a bug and fixed by Michael Meskes. If you need the solution, apply the fix yourself fist.
diff --git a/src/interfaces/ecpg/ecpglib/data.c b/src/interfaces/ecpg/ecpglib/data.c
index 8d36484..82ab4aa 100644
--- a/src/interfaces/ecpg/ecpglib/data.c
+++ b/src/interfaces/ecpg/ecpglib/data.c
## -423,27 +423,13 ## ecpg_get_data(const PGresult *results, int act_tuple, int act_field, int lineno,
case ECPGt_bool:
if (pval[0] == 'f' && pval[1] == '\0')
{
- if (offset == sizeof(char))
- *((char *) (var + offset * act_tuple)) = false;
- else if (offset == sizeof(int))
- *((int *) (var + offset * act_tuple)) = false;
- else
- ecpg_raise(lineno, ECPG_CONVERT_BOOL,
- ECPG_SQLSTATE_DATATYPE_MISMATCH,
- NULL);
+ *((bool *) (var + offset * act_tuple)) = false;
pval++;
break;
}
else if (pval[0] == 't' && pval[1] == '\0')
{
- if (offset == sizeof(char))
- *((char *) (var + offset * act_tuple)) = true;
- else if (offset == sizeof(int))
- *((int *) (var + offset * act_tuple)) = true;
- else
- ecpg_raise(lineno, ECPG_CONVERT_BOOL,
- ECPG_SQLSTATE_DATATYPE_MISMATCH,
- NULL);
+ *((bool *) (var + offset * act_tuple)) = true;
pval++;
break;
}
diff --git a/src/interfaces/ecpg/ecpglib/execute.c b/src/interfaces/ecpg/ecpglib/execute.c
index 9e40f41..3b6eedb 100644
--- a/src/interfaces/ecpg/ecpglib/execute.c
+++ b/src/interfaces/ecpg/ecpglib/execute.c
## -752,18 +752,9 ## ecpg_store_input(const int lineno, const bool force_indicator, const struct vari
{
strcpy(mallocedval, "{");
- if (var->offset == sizeof(char))
- for (element = 0; element < asize; element++)
- sprintf(mallocedval + strlen(mallocedval), "%c,", (((char *) var->value)[element]) ? 't' : 'f');
+ for (element = 0; element < asize; element++)
+ sprintf(mallocedval + strlen(mallocedval), "%c,", (((bool *) var->value)[element]) ? 't' : 'f');
- /*
- * this is necessary since sizeof(C++'s bool)==sizeof(int)
- */
- else if (var->offset == sizeof(int))
- for (element = 0; element < asize; element++)
- sprintf(mallocedval + strlen(mallocedval), "%c,", (((int *) var->value)[element]) ? 't' : 'f');
- else
- ecpg_raise(lineno, ECPG_CONVERT_BOOL, ECPG_SQLSTATE_DATATYPE_MISMATCH, NULL);
strcpy(mallocedval + strlen(mallocedval) - 1, "}");
}