সি/সি++ ব্যবহার করে ডেটাবেস কানেক্টিভিটি (Database Connectivity)

এই সেকশনে আপনি শিখবেন কীভাবে সি/সি++ প্রোগ্রামে SQLite ব্যবহার করতে হয়।

ইনস্টলেশন

SQLite সি/সি++ প্রোগ্রামে ব্যবহার করার আগে নিশ্চিত করুন যে আপনার মেশিনে SQLite লাইব্রেরি সেটআপ করা আছে। ইনস্টলেশন প্রসেস জানতে SQLite Installation চ্যাপ্টার দেখুন।

C/C++ ইন্টারফেস API-ها

নিচে গুরুত্বপূর্ণ C/C++ SQLite ইন্টারফেস রুটিনগুলো দেওয়া আছে:

sqlite3_open(const char *filename, sqlite3 **ppDb)

sqlite3_exec(sqlite3*, const char *sql, sqlite_callback, void *data, char **errmsg)

sqlite3_close(sqlite3*)

ডেটাবেস কানেক্ট করা

#include <stdio.h>
#include <sqlite3.h>
int main(int argc, char* argv[]) {
    sqlite3 *db;
    char *zErrMsg = 0;
    int rc;
    rc = sqlite3_open("test.db", &db);
    if (rc) {
        fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
        return 0;
    } else {
        fprintf(stderr, "Opened database successfully\n");
    }
    sqlite3_close(db);
    return 0;
}

আউটপুট

$gcc test.c -l sqlite3
$./a.out
Opened database successfully

টেবিল তৈরি করা (Create Table)

#include <stdio.h>
#include <stdlib.h>
#include <sqlite3.h>
static int callback(void *NotUsed, int argc, char **argv, char **azColName) {
    int i;
    for (i = 0; i < argc; i++) {
        printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
    }
    printf("\n");
    return 0;
}
int main(int argc, char* argv[]) {
    sqlite3 *db;
    char *zErrMsg = 0;
    int rc;
    char *sql;
    rc = sqlite3_open("test.db", &db);
    if (rc) {
        fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
        return 0;
    } else {
        fprintf(stdout, "Opened database successfully\n");
    }
    sql = "CREATE TABLE COMPANY("
          "ID INT PRIMARY KEY NOT NULL,"
          "NAME TEXT NOT NULL,"
          "AGE INT NOT NULL,"
          "ADDRESS CHAR(50),"
          "SALARY REAL );";
    rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);
    if (rc != SQLITE_OK) {
        fprintf(stderr, "SQL error: %s\n", zErrMsg);
        sqlite3_free(zErrMsg);
    } else {
        fprintf(stdout, "Table created successfully\n");
    }
    sqlite3_close(db);
    return 0;
}

আউটপুট (ডেটাবেস ফাইল স্ট্যাটাস)

-rwxr-xr-x. 1 root root 9567 May 8 02:31 a.out
-rw-r--r--. 1 root root 1207 May 8 02:31 test.c
-rw-r--r--. 1 root root 3072 May 8 02:31 test.db

ইনসার্ট অপারেশন (Insert Operation)

/* ... similar code ... */
sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (1, 'Paul', 32, 'California', 20000.00 );"
      "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (2, 'Allen', 25, 'Texas', 15000.00 );"
      "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );"
      "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (4, 'Mark', 25, 'Rich-Mond', 65000.00 );";
rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);
fprintf(stdout, "Records created successfully\n");
sqlite3_close(db);

আউটপুট

Opened database successfully
Records created successfully

সিলেক্ট অপারেশন (SELECT Operation)

/* ... callback function ... */
sql = "SELECT * from COMPANY";
rc = sqlite3_exec(db, sql, callback, (void*)data, &zErrMsg);
fprintf(stdout, "Operation done successfully\n");
sqlite3_close(db);

আউটপুট

Opened database successfully
Callback function called: ID = 1 NAME = Paul AGE = 32 ADDRESS = California SALARY = 20000.0
Callback function called: ID = 2 NAME = Allen AGE = 25 ADDRESS = Texas SALARY = 15000.0
Callback function called: ID = 3 NAME = Teddy AGE = 23 ADDRESS = Norway SALARY = 20000.0
Callback function called: ID = 4 NAME = Mark AGE = 25 ADDRESS = Rich-Mond SALARY = 65000.0
Operation done successfully