sqlite3使用

Posted 2021-05-29 Overboom

/*
@brief 本程序测试sqlite数据库的增删改查
@date 2012-09-03
*/
// SQLiteTest.cpp : Defines the entry point for the console application.
// 
 
//#include "stdafx.h"
#include "sqlite3.h"
#include <iostream>
using namespace std;
 
sqlite3 * pDB = NULL;
 
bool CreateTable();

//增加用户
bool AddUser(const string& sName, const string& sAge);
//删除用户
bool DeleteUser(const string& sName);
//修改用户
bool ModifyUser(const string& sName, const string& sAge);
//查找用户
bool SelectUser();
 
int main(void)
{
    //打开路径采用utf-8编码
    //如果路径中包含中文，需要进行编码转换
	
    CreateTable();

    int nRes = sqlite3_open("test.db", &pDB);
    if (nRes != SQLITE_OK)
    {
        cout<<"Open database fail: "<<sqlite3_errmsg(pDB);
        goto QUIT;
    }

	
 
    //添加“赵钱孙李”
    if (    !AddUser("zhao", "18")
        || !AddUser("qian", "19")
        || !AddUser("sun", "20")
        || !AddUser("li", "21"))
    {
        goto QUIT;
    }
 
    //删除“赵”
    if (!DeleteUser("zhao"))
    {
        goto QUIT;
    }
 
    //修改“孙”
    if (!ModifyUser("sun", "15"))
    {
        goto QUIT;
    }

    cout << "find the user" << endl;
 
    //查找用户
    if (!SelectUser())
    {
        goto QUIT;
    }
 
QUIT:
    sqlite3_close(pDB);
 
    return 0;
}


static int callback(void *NotUsed, int argc, char **argv, char **azColName)
{
    int i = 0;
    for(i = 0; i < argc; i++)
    {
        printf("%s = %s\\n",azColName[i], argv[i]?argv[i]:"NULL");
    }
 
    printf("\\n");
    return 0;
}



bool CreateTable()
{
    char *zErrMsg = 0;
    int rc;
    char *sql;
 
    rc = sqlite3_open("test.db", &pDB);  // 打开数据库
    if(rc)
    {
        fprintf(stderr, "Can't open database:%s\\n", sqlite3_errmsg(pDB));
        return false;
    }
    else
    {
        fprintf(stderr,"open database succeddfully\\n");
    }
 
    // sql = "create table company( "\\
	// 			"ID INT PRIMARY KEY NOT NULL,"\\
	// 			"NAME TEXT NOT NULL,"\\
	// 			"AGE TEXT NOT NULL);";

   sql = "CREATE TABLE user("  \\
         "NAME           TEXT    NOT NULL," \\
         "AGE            INT     NOT NULL," \\
         "ADDRESS        CHAR(50)," \\
         "SALARY         REAL );";
 
    rc = sqlite3_exec(pDB, sql, callback, 0, &zErrMsg); // 执行上面sql中的命令
    if(SQLITE_OK != rc)
    {
        fprintf(stderr, "SQL error: %s\\n", zErrMsg);
    }
    else
    {
        fprintf(stdout, "create table successfully\\n");
    }

}

 
bool AddUser(const string& sName, const string& sAge)
{
    string strSql = "";
    strSql += "insert into user(name,age)";
    strSql += "values('";
    strSql += sName;
    strSql += "',";
    strSql += sAge;
    strSql += ");";
 
    char* cErrMsg;
    int nRes = sqlite3_exec(pDB , strSql.c_str() ,0 ,0, &cErrMsg);
    if (nRes != SQLITE_OK)  
    {
        cout<<"add user fail: "<<cErrMsg<<endl;
        return false;
    }
    else
    {
        cout<<"add user success: "<<sName.c_str()<<"\\t"<<sAge.c_str()<<endl;
    }
 
    return true;
}
 
bool DeleteUser(const string& sName)
{
    string strSql = "";
    strSql += "delete from user where name='";
    strSql += sName;
    strSql += "';";
 
    char* cErrMsg;
    int nRes = sqlite3_exec(pDB , strSql.c_str() ,0 ,0, &cErrMsg);
    if (nRes != SQLITE_OK)  
    {
        cout<<"delete user fail: "<<cErrMsg<<endl;
        return false;
    }
    else
    {
        cout<<"delete user success: "<<sName.c_str()<<endl;
    }
 
    return true;
}
 
bool ModifyUser(const string& sName, const string& sAge)
{
    string strSql = "";
    strSql += "update user set age =";
    strSql += sAge;
    strSql += " where name='";
    strSql += sName;
    strSql += "';";
 
    char* cErrMsg;
    int nRes = sqlite3_exec(pDB , strSql.c_str() ,0 ,0, &cErrMsg);
    if (nRes != SQLITE_OK)  
    {
        cout<<"modify user fail: "<<cErrMsg<<endl;
        return false;
    }
    else
    {
        cout<<"modify user success: "<<sName.c_str()<<"\\t"<<sAge.c_str()<<endl;
    }
 
    return true;
}
 
// static int UserResult(void *NotUsed, int argc, char **argv, char **azColName)
// {
//     for(int i = 0 ; i < argc ; i++)
//     {
//         cout<<azColName[i]<<" = "<<(argv[i] ? argv[i] : "NULL")<<", ";
//     }
//     cout<<endl;
 
//     return 0;
// }


// static int UserResult(void *data, int argc, char **argv, char **azColName){
//    int i;
//    fprintf(stderr, "%s: ", (const char*)data);
//    for(i=0; i<argc; i++){
//       printf("%s = %s\\n", azColName[i], argv[i] ? argv[i] : "NULL");
//    }
//    printf("\\n");
//    return 0;
// }
 
bool SelectUser()
{
    char* cErrMsg;
    int res = sqlite3_exec(pDB, "select * from user;", callback , 0 , &cErrMsg);  
 
    if (res != SQLITE_OK)
    {
        cout<<"select fail: "<<cErrMsg<<endl;
        return false;
    }
    cout << "find the user end---" << endl;
 
    return true;
}