Example of how to run sqlite3_deserialize

run_sqlite3_deserialize.c

#include <sqlite3.h>
#include <stdio.h>
#include <stdlib.h>

#define MAX_FILE_SIZE 1000000

// build with
// cc run_sqlite3_deserialize.c -lsqlite3 -o sqlite3_deserialize
// create db with:
// echo "create table pizza(name, color); insert into pizza(name, color) values ('margarita', 'red');" | sqlite3 pizza.db

int callback(void *, int, char **, char **);
int load(sqlite3 *db, char *name, unsigned char *dbuf, unsigned long *fileLen);

int main(void) {
    
    sqlite3 *db;
    char *err_msg = 0;
    unsigned char *dbuf = malloc(sizeof(unsigned char)*MAX_FILE_SIZE);
    unsigned long fileLen;
    
    int rc = sqlite3_open(":memory:", &db);
    
    if (rc != SQLITE_OK) {
        
        fprintf(stderr, "Cannot open database: %s\n", 
                sqlite3_errmsg(db));
        sqlite3_close(db);
        
        return 1;
    }

    load(db, "pizza.db", dbuf, &fileLen);
    free(dbuf);
    
    char *sql = "SELECT * FROM pizza";
        
    rc = sqlite3_exec(db, sql, callback, 0, &err_msg);
    
    if (rc != SQLITE_OK ) {
        
        fprintf(stderr, "Failed to select data\n");
        fprintf(stderr, "SQL error: %s\n", err_msg);

        sqlite3_free(err_msg);
        sqlite3_close(db);
        
        return 1;
    } 
    
    sqlite3_close(db);
    
    return 0;
}

int load(sqlite3 *db, char *name, unsigned char *dbuf, unsigned long *fileLen)
{
  FILE *file;

  //Open file
  file = fopen(name, "rb");
  if (!file)
  {
    fprintf(stderr, "Unable to open file %s", name);
    return 1;
  }
  
  //Get file length
  fseek(file, 0, SEEK_END);
  *fileLen=ftell(file);
  fseek(file, 0, SEEK_SET);

  //Read file contents into buffer
  fread(dbuf, *fileLen, 1, file);
  fclose(file);

  printf("File size: %ld\n", *fileLen);

  sqlite3_deserialize(db, NULL, dbuf, *fileLen, *fileLen, 0);

  return 0;
}

int callback(void *NotUsed, int argc, char **argv, 
                    char **azColName) {
    
    NotUsed = 0;
    
    for (int i = 0; i < argc; i++) {

        printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
    }
    
    printf("\n");
    
    return 0;
}