c ++:使用SQLite创建数据库以进行插入和更新

Question

我正在尝试使用sqlite3 lib在c ++中创建数据库.我收到错误sqlite3_prepare_v2'
未在此范围内声明,如logcat中所示.

日志文件

..\src\Test.cpp: In function 'int main(int, const char**)':
..\src\Test.cpp:21:85: error: 'sqlite3_prepare_v2' was not declared in this scope
..\src\Test.cpp:30:13: error: variable 'sqlite3 in' has initializer but incomplete type
..\src\Test.cpp:30:30: error: invalid use of incomplete type 'sqlite3 {aka struct sqlite3}'
..\src\/sqlite3.h:73:16: error: forward declaration of 'sqlite3 {aka struct sqlite3}'

这是我的代码

#include <iostream>
using namespace std;
 #include "sqlite3.h"

 int main (int argc, const char * argv[]) {

sqlite3 *db;
sqlite3_open("test.db", & db);

   string createQuery = "CREATE TABLE IF NOT EXISTS items (busid INTEGER PRIMARY KEY, ipaddr TEXT,    time TEXT NOT NULL DEFAULT (NOW()));";
   sqlite3_stmt *createStmt;
  cout << "Creating Table Statement" << endl;
  sqlite3_prepare_v2(db, createQuery.c_str(), createQuery.size(), &createStmt, NULL);
   cout << "Stepping Table Statement" << endl;
   if (sqlite3_step(createStmt) != SQLITE_DONE) cout << "Didn't Create Table!" << endl;

   string insertQuery = "INSERT INTO items (time, ipaddr) VALUES ('test', '192.168.1.1');"; // WORKS!


   sqlite3_stmt *insertStmt;
   cout << "Creating Insert Statement" << endl;
   sqlite3_prepare(db, insertQuery.c_str(), insertQuery.size(), &insertStmt, NULL);
   cout << "Stepping Insert Statement" << endl;
   if (sqlite3_step(insertStmt) != SQLITE_DONE) cout << "Didn't Insert Item!" << endl;

cout << "Success!" << endl;

 return 0;
}

请帮帮我.谢谢.....

Answer 1

 #include <sqlite3.h>

应该包含sqlite3_prepare_v2和struct sqlite3.确保包含正确的sqlite3.h文件.

同样在sqlite3_prepare_v2中,第3个arg可以(并且应该在你的情况下)-1,因此sql被读取到第一个空终止符.

使用sqlite 3.7.11处理裸金属样本:

#include <sqlite3.h>
int test()
{
    sqlite3* pDb = NULL;
    sqlite3_stmt* query = NULL;
    int ret = 0;
    do // avoid nested if's
    {
        // initialize engine
        if (SQLITE_OK != (ret = sqlite3_initialize()))
        {
            printf("Failed to initialize library: %d\n", ret);
            break;
        }
        // open connection to a DB
        if (SQLITE_OK != (ret = sqlite3_open_v2("test.db", &pDb, SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, NULL)))
        {
            printf("Failed to open conn: %d\n", ret);
            break;
        }
        // prepare the statement
        if (SQLITE_OK != (ret = sqlite3_prepare_v2(pDb, "SELECT 2012", -1, &query, NULL)))
        {
            printf("Failed to prepare insert: %d, %s\n", ret, sqlite3_errmsg(pDb));
            break;
        }
        // step to 1st row of data
        if (SQLITE_ROW != (ret = sqlite3_step(query))) // see documentation, this can return more values as success
        {
            printf("Failed to step: %d, %s\n", ret, sqlite3_errmsg(pDb));
            break;
        }
        // ... and print the value of column 0 (expect 2012 here)
        printf("Value from sqlite: %s", sqlite3_column_text(query, 0));     

    } while (false);
    // cleanup
    if (NULL != query) sqlite3_finalize(query);
    if (NULL != pDb) sqlite3_close(pDb);
    sqlite3_shutdown();
    return ret;
}

希望这可以帮助

Answer 2

伙计们,使用c/c ++中的sqlite3创建数据库,这里我正在使用以下步骤...

1) Firstly you include MinGw file .
2) Add header file sqlite3.h, sqlite3.c in your src folder.
3) Add libr folder , in libr here include these file

    mysqlite.h, shell.c, sqlite3.c, sqlite3.h, sqlite3ext.h

然后开始编码...

     #include <iostream>
 using namespace std;
 #include "sqlite3.h"

 int main (int argc, const char * argv[]) {

    sqlite3 *db;
    sqlite3_open("test1.db", & db);

  string createQuery = "CREATE TABLE IF NOT EXISTS items (userid INTEGER PRIMARY KEY, ipaddr
      TEXT,username TEXT,useradd TEXT,userphone INTEGER,age INTEGER, "
                                                    "time TEXT NOT NULL DEFAULT 
                                                                             (NOW()));";
    sqlite3_stmt *createStmt;
    cout << "Creating Table Statement" << endl;
    sqlite3_prepare(db, createQuery.c_str(), createQuery.size(), &createStmt, NULL);
    cout << "Stepping Table Statement" << endl;
    if (sqlite3_step(createStmt) != SQLITE_DONE) cout << "Didn't Create Table!" << endl;

    string insertQuery = "INSERT INTO items (time, ipaddr,username,useradd,userphone,age) 
        VALUES ('7:30', '192.187.27.55','vivekanand','kolkatta','04456823948',74);"; // WORKS!
    sqlite3_stmt *insertStmt;
    cout << "Creating Insert Statement" << endl;
    sqlite3_prepare(db, insertQuery.c_str(), insertQuery.size(), &insertStmt, NULL);
    cout << "Stepping Insert Statement" << endl;
    if (sqlite3_step(insertStmt) != SQLITE_DONE) cout << "Didn't Insert Item!" << endl;  



         return 0;
     }