SQLite3 How to handle column index out of range - c++

Question

Whenever I want to insert a type object (define below) in the database I get "error 25 : column index out of range".
Which means that the value I try to bind doesn't fit in the query right?
CREATE TABLE color (
id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
label TEXT NOT NULL
);
CREATE TABLE IF NOT EXISTS object (
id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
label TEXT NOT NULL,
color_id INTEGER,
position_x REAL,
position_y REAL,
position_z REAL,
distance REAL,
FOREIGN KEY(color_id) REFERENCES color(id)
);
-- few insert to populate color
INSERT INTO color(id,label) VALUES (1,'Black');
INSERT INTO color(id,label) VALUES (2,'White');
INSERT INTO color(id,label) VALUES (3,'Red');
INSERT INTO color(id,label) VALUES (4,'Lime');
INSERT INTO color(id,label) VALUES (5,'Blue');
INSERT INTO color(id,label) VALUES (6,'Yellow');
I tried putting the query using the CLI interface and this worked.
insert into object (label,color_id,position_x,position_y,position_z,distance) values ("can",2,0.2,0.2,0.2,1.2);
I checked the number of fields, the name of variables, my database is open when my class is created and close on destruction. And last colorIndex is an int that I retrieve from a function I already use to insert other element in a different table. I also printed the values and they are correct.
I guess I m missing something here. I can't see where else can be my mistake.
typedef struct Object{
std::string label;
std::string color;
float pos_x;
float pos_y;
float pos_z;
float distance;
} Object;
int VisionModel::getColorByLabel(std::string sColor){
int colorId;
query = "SELECT id FROM color WHERE label = (?)";
pStmt = nullptr;
int rc;
rc = sqlite3_prepare_v2(db,query.c_str(), -1, &pStmt, NULL);
if (rc != SQLITE_OK){
std::cout << "prepare getColorByLabel didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return colorId;
}
if (sqlite3_bind_text(pStmt, 1, sColor.c_str(), -1, NULL) != SQLITE_OK){
std::cout << "bind color label didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return colorId;
}
while ( (rc = sqlite3_step(pStmt)) == SQLITE_ROW) {
colorId = sqlite3_column_int(pStmt, 0);
}
sqlite3_finalize(pStmt);
return colorId;
}
void VisionModel::createObject(Object object){
query = "INSERT INTO object (label,color_id,position_x,position_y,position_z,distance) VALUES (?,?,?,?,?,?)";
pStmt = nullptr;
int rc;
// get the index for given color
int colorIndex = -1;
if (!object.color.empty() && object.color != "0"){
colorIndex = getColorByLabel(object.color);
}
rc = sqlite3_prepare_v2(db,query.c_str(), -1, &pStmt, NULL);
if (rc != SQLITE_OK){
std::cout << "prepare createObject didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return ;
}
if (sqlite3_bind_text(pStmt, 1, object.label.c_str(), -1, NULL) != SQLITE_OK){
std::cout << "bind object label didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return ;
}
if (colorIndex != -1){
rc = sqlite3_bind_int(pStmt, 2, colorIndex);
if ( rc != SQLITE_OK){
std::cout << "bind object color index didn t went through" << std::endl;
std::cout << std::to_string(colorIndex) << std::endl;
manageSQLiteErrors(pStmt);
return ;
}
}
if (sqlite3_bind_double(pStmt, 3, object.pos_x) != SQLITE_OK){
std::cout << "bind object pos x didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return ;
}
if (sqlite3_bind_double(pStmt, 4, object.pos_y) != SQLITE_OK){
std::cout << "bind person object y didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return ;
}
if (sqlite3_bind_double(pStmt, 5, object.pos_z) != SQLITE_OK){
std::cout << "bind person object z didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return ;
}
if (sqlite3_bind_double(pStmt, 6, object.distance) != SQLITE_OK){
std::cout << "bind person object distance didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return ;
}
if ((rc = sqlite3_step(pStmt)) != SQLITE_DONE) { /* 2 */
std::cout << "step didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return ;
}
sqlite3_finalize(pStmt);
}
Here is a minimal reproductible version of the code that you can copy paste and compile. Don't forget to create the database with the query above first.
compile : g++ -o main main.cpp -lsqlite3
code :
#include <string>
#include <iostream>
#include <sqlite3.h>
typedef struct Object
{
std::string label;
std::string color;
float pos_x;
float pos_y;
float pos_z;
float distance;
} Object;
class VisionModel
{
private:
sqlite3 *db;
const char *zErrMsg = 0;
std::string query;
sqlite3_stmt *pStmt;
public:
VisionModel()
{
connect();
}
~VisionModel()
{
close();
}
void connect()
{
int rc;
std::string db_file_path("./database.db");
rc = sqlite3_open(db_file_path.c_str(), &db);
if (rc)
{
std::cerr << "Can't open database" << sqlite3_errmsg(db) << std::endl;
std::cerr << "SQL code error : " << sqlite3_extended_errcode(db) << std::endl;
return;
}
};
void manageSQLiteErrors(sqlite3_stmt *pStmt)
{
std::cerr << "SQL error : " << sqlite3_errmsg(db) << std::endl;
std::cerr << "SQL code error : " << sqlite3_extended_errcode(db) << std::endl;
sqlite3_finalize(pStmt);
}
void close()
{
sqlite3_close(db);
};
int getColorByLabel(std::string sColor)
{
int colorId;
query = "SELECT id FROM color WHERE label = (?)";
pStmt = nullptr;
int rc;
rc = sqlite3_prepare_v2(db, query.c_str(), -1, &pStmt, NULL);
if (rc != SQLITE_OK)
{
std::cout << "prepare getColorByLabel didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return colorId;
}
if (sqlite3_bind_text(pStmt, 1, sColor.c_str(), -1, NULL) != SQLITE_OK)
{
std::cout << "bind color label didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return colorId;
}
while ((rc = sqlite3_step(pStmt)) == SQLITE_ROW)
{
colorId = sqlite3_column_int(pStmt, 0);
}
sqlite3_finalize(pStmt);
return colorId;
}
void createObject(Object object)
{
query = "INSERT INTO object (label,color_id,position_x,position_y,position_z,distance) VALUES (?,?,?,?,?,?)";
pStmt = nullptr;
int rc;
// get the index for given color
int colorIndex = -1;
if (!object.color.empty() && object.color != "0")
{
colorIndex = getColorByLabel(object.color);
}
rc = sqlite3_prepare_v2(db, query.c_str(), -1, &pStmt, NULL);
if (rc != SQLITE_OK)
{
std::cout << "prepare createObject didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return;
}
if (sqlite3_bind_text(pStmt, 1, object.label.c_str(), -1, NULL) != SQLITE_OK)
{
std::cout << "bind object label didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return;
}
if (colorIndex != -1)
{
rc = sqlite3_bind_int(pStmt, 2, colorIndex);
if (rc != SQLITE_OK)
{
std::cout << "bind object color index didn t went through" << std::endl;
std::cout << std::to_string(colorIndex) << std::endl;
manageSQLiteErrors(pStmt);
return;
}
}
if (sqlite3_bind_double(pStmt, 3, object.pos_x) != SQLITE_OK)
{
std::cout << "bind object pos x didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return;
}
if (sqlite3_bind_double(pStmt, 4, object.pos_y) != SQLITE_OK)
{
std::cout << "bind person object y didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return;
}
if (sqlite3_bind_double(pStmt, 5, object.pos_z) != SQLITE_OK)
{
std::cout << "bind person object z didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return;
}
if (sqlite3_bind_double(pStmt, 6, object.distance) != SQLITE_OK)
{
std::cout << "bind person object distance didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return;
}
if ((rc = sqlite3_step(pStmt)) != SQLITE_DONE)
{ /* 2 */
std::cout << "step didn t went through" << std::endl;
manageSQLiteErrors(pStmt);
return;
}
sqlite3_finalize(pStmt);
}
};
int main()
{
Object obj = {"apple", "Blue", 0.1, 0.2, 0.1, 2.0};
VisionModel vm;
vm.createObject(obj);
}

Answer 1

If you used your debugger to show the value of query here, the problem becomes very easy to see:
rc = sqlite3_prepare_v2(db, query.c_str(), -1, &pStmt, NULL);
You will discover that this query is not really the INSERT statement that you think it is.
This is because just a few lines earlier:
colorIndex = getColorByLabel(object.color);
And this ends up clobbering the query variable, setting it to a "SELECT" with just one ? placeholder.
You can use this as a golden opportunity to learn how to use a debugger, which makes solving these Scooby-Doo mysteries simple. Try to use the shown program in your debugger, exactly as is, setting a breakpoint at the sqlite3_prepare_v2 line in createObject, and then inspecting what's in the query, and having your own "Eureka!" moment.