c++ - SQLite Blob 插入 C++

Question

在访问了数十个包含有关 SQLite 信息的网站后，我仍然找不到修复绑定(bind) blob 时错误的解决方案。这是表减速:

CREATE TABLE ONE ( 
ID    INTEGER     PRIMARY KEY AUTOINCREMENT
                  NOT NULL,
NAME  CHAR( 50 )  NOT NULL,
LABEL CHAR( 50 ),
GRP   CHAR( 50 ),
FILE  BLOB 
);

插入代码如下:

int InsertFile(string name)
{
const char* dbname = name.c_str();
sqlite3 *database;
int rc = sqlite3_open(dbname, &database);
char *zErrMsg = 0;
unsigned char *buffer = (unsigned char*) malloc(sizeof(char)*MAX);

ifstream file;
file.open("Sql.pdf", ios::in|ios::binary);

    if ( ! file )
{
        cout << "An error occurred opening the file" << endl;
}

int count = 0;

const void* fileptr = NULL;


fileptr = buffer;

while(file.good())
{
    char c=file.get();
    buffer[count]=c;
    count++;
}
file.close();


sqlite3_stmt *stmt = NULL;

char* statement = "INSERT INTO ONE(     ID,    NAME,    LABEL,    GRP,    FILE ) VALUES (     NULL,    'fedfsdfss',    NULL,    NULL,  ?);";

rc = sqlite3_prepare_v2(database, statement, 0, &stmt, NULL);


rc = sqlite3_bind_blob(stmt, 1, fileptr, sizeof(char)*count, SQLITE_TRANSIENT);


const char* result = sqlite3_errmsg(database);


rc = sqlite3_step(stmt);

result = sqlite3_errmsg(database);

sqlite3_close(database);


free(buffer);

fileptr=NULL;

return 0;

} 编辑:粘贴完整功能，我尝试插入的字符数量约为 350K。

binb_blob 的结果始终为 21，错误代码不包含任何内容。缓冲区包含二进制文件数据，这很可能不是太大，因此错误代码。任何提示将不胜感激。

Answer 1

您的代码错误太多，无法统计。

尝试这样的事情:

int InsertFile(const string& db_name)
{
    ifstream file("Sql.pdf", ios::in | ios::binary);
    if (!file) {
        cerr << "An error occurred opening the file\n";
        return 12345;
    }
    file.seekg(0, ifstream::end);
    streampos size = file.tellg();
    file.seekg(0);

    char* buffer = new char[size];
    file.read(buffer, size);

    sqlite3 *db = NULL;
    int rc = sqlite3_open_v2(db_name.c_str(), &db, SQLITE_OPEN_READWRITE, NULL);
    if (rc != SQLITE_OK) {
        cerr << "db open failed: " << sqlite3_errmsg(db) << endl;
    } else {
        sqlite3_stmt *stmt = NULL;
        rc = sqlite3_prepare_v2(db,
                                "INSERT INTO ONE(ID, NAME, LABEL, GRP, FILE)"
                                " VALUES(NULL, 'fedfsdfss', NULL, NULL, ?)",
                                -1, &stmt, NULL);
        if (rc != SQLITE_OK) {
            cerr << "prepare failed: " << sqlite3_errmsg(db) << endl;
        } else {
            // SQLITE_STATIC because the statement is finalized
            // before the buffer is freed:
            rc = sqlite3_bind_blob(stmt, 1, buffer, size, SQLITE_STATIC);
            if (rc != SQLITE_OK) {
                cerr << "bind failed: " << sqlite3_errmsg(db) << endl;
            } else {
                rc = sqlite3_step(stmt);
                if (rc != SQLITE_DONE)
                    cerr << "execution failed: " << sqlite3_errmsg(db) << endl;
            }
        }
        sqlite3_finalize(stmt);
    }
    sqlite3_close(db);

    delete[] buffer;
}