sqlite3的使用
sqlite3的使用
splite.hpp
/*封装实现一个sqliteHelper类，提供简单的sqlite数据库接口，完成数据的基础增删改查操作1.创建/打开数据库2.针对打开的数据库进行操作1.表的操作2.数据的操作3.关闭数据库
*/#include <iostream>
#include <string>
#include <vector>
#include <sqlite3.h>class SqliteHelper
{public:typedef int(*SqliteCallback)(void*,int ,char**,char**);SqliteHelper(const std::string &dbfile):_dbfile(dbfile),_handler(nullptr){}bool open(int safe_level=SQLITE_OPEN_FULLMUTEX){//int sqlite3_open_v2(const char *filename, sqlite3 **ppDb, int flags, const char *zVfs );int ret=sqlite3_open_v2(_dbfile.c_str(),&_handler,SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | safe_level,nullptr);if(ret!=SQLITE_OK){std::cout<<"创建/打开sqlite数据库失败";std::cout<<sqlite3_errmsg(_handler)<<std::endl;return false;}return true;}bool exec(const std::string &sql,SqliteCallback cb,void *arg){//int sqlite3_exec(sqlite3*, char *sql, int (*callback)(void*,int,char**,char**), void* arg, char **err)int ret=sqlite3_exec(_handler,sql.c_str(),cb,arg,nullptr);if(ret!=SQLITE_OK){std::cout<<sql<<std::endl;std::cout<<"执行语句失败！";std::cout<<sqlite3_errmsg(_handler)<<std::endl;return false;}return true;}void close(){// int sqlite3_close_v2(sqlite3*)if(_handler) sqlite3_close_v2(_handler);}private:std::string _dbfile;sqlite3* _handler;
};
main.cc
#include "sqlite.hpp"
#include <cassert>int select_stu_callback(void*arg,int col_count,char**result,char**fields_name)
{std::vector<std::string> *arry=(std::vector<std::string>*)arg;arry->push_back(result[0]);return 0;//必须有！
}
int main()
{SqliteHelper helper("./test.db");//1.打开/创建库文件assert(helper.open());//2.创建表，学生信息：学号，姓名，年龄const char* ct="create table if not exists student(sn int primary key,name varchar(32),age int)";assert(helper.exec(ct,nullptr,nullptr));//3.新增数据，删除，修改，查询//const char* insert_sql="insert into student values(1,'小明',18),(2,'小黑',19),(3,'小红',18)";//assert(helper.exec(insert_sql,nullptr,nullptr));//const char *update_sql="update student set name ='张小明' where sn=1";//assert(helper.exec(update_sql,nullptr,nullptr));//const char *delete_sql="delete from student where sn=3";//assert(helper.exec(delete_sql,nullptr,nullptr));const char *select_sql="select name from student ;";std::vector<std::string> arry;assert(helper.exec(select_sql,select_stu_callback,&arry));for(auto &name: arry){std::cout<<name<<std::endl;}//4.关闭数据库helper.close();return 0;
}
makefile
main:main.ccg++ -std=c++11 $^ -o $@ -lsqlite3