SQLite3的绑定函数族使用与其注意事项详解

(编辑:jimmy 日期: 2025/2/25 浏览:2)

前言

本文给大家展示的代码实际上就是如何利用Sqlite3的参数化机制做数据插入,也可以update操作,就看你怎么玩了,这里只列出代码,然后说一些注意事项。

下面的代码,有一个问题,插入后的东西一定是:

INSERT INTO "work" VALUES('铪','铪铪铪铪铪',NULL,NULL,NULL,NULL,'铪铪铪铪铪',NULL,NULL,110.0,1.0,108.9,NULL,NULL,'铪铪铪铪铪',NULL,NULL,NULL,'铪铪铪铪铪',NULL,NULL,NULL);

看看有问题的代码:

sqlite3_stmt *stmt;
 CString sql = "insert into work values (";
 int rc = sqlite3_prepare_v2(db, sql.GetString(), -1, &stmt, NULL);

 if(rc != SQLITE_OK)
 {
 MessageBox("sqlite3_prepare_v2 Failed!");
 return;
 }

 count = 0;
 p_wnd = PrevWnd;

 while(count++ < ID_TOTALCOUNT)
 {
 CString DbStr;
 
 p_wnd = CWnd::GetNextDlgTabItem(p_wnd, FALSE); 
 if(p_wnd == NULL)
 {
  return;
 }

 p_wnd->GetWindowText(DbStr);

 do
 {
  if(!DbStr.GetLength())
  {
  rc = sqlite3_bind_null(stmt, count);
  break;
  }

  //日期相关
  if( count == ID_CHUDANRIQI || 
  count == ID_CHUFARIQI || 
  count == ID_HUANKUANRIQI || 
  count == ID_HUOLIRIQI)
  {
  CDateTimeCtrl *TimeCtl = (CDateTimeCtrl *)p_wnd;  
  CString time = DateTimeToString(*TimeCtl);

  rc = sqlite3_bind_text(stmt, count, time.GetString(), time.GetLength(), SQLITE_STATIC);
  break;
  }
  else
  {
  //金钱相关的处理real类型
  if( count == ID_BAOXIANJINE || 
   count == ID_YONGJINBILV || 
   count == ID_JINGBAOFEI || 
   count == ID_HUANKUANJINE || 
   count == ID_LIRUNBILV || 
   count == ID_LIRUNJINE)
  {
   double tMoney = 0.0;
   int rtn = sscanf_s(DbStr.GetString(), "%lf", &tMoney);

   ASSERT(rtn == 1);

   rc = sqlite3_bind_double(stmt, count, tMoney);
  }
  else
  {
   char *str = (char *)DbStr.GetString();
   int c = strlen(str);
   int c1 = DbStr.GetLength();

   rc = sqlite3_bind_text(stmt, count, DbStr.GetString(), -1/*DbStr.GetLength()*/, SQLITE_STATIC);
  }
  }
 }while(0);

 if(rc != SQLITE_OK)
 {
  CString ErrStr = sqlite3_errstr(rc);
  MessageBox(ErrStr);

  return;
 }
 }

 rc = sqlite3_step(stmt); 

 if(rc != SQLITE_DONE)
 {
 if(rc == SQLITE_ERROR)
 {
  CString DbErr;
  DbErr.Format("Sql Insert failed, %s", sqlite3_errmsg(db));

  MessageBox(DbErr);
 }
 else
 {
  MessageBox("sqlite3_step Failed!");
 } 
 }

 sqlite3_finalize(stmt);

为什么呢?

因为,sqlite3_bind_text绑定的text,需要在做:

rc = sqlite3_step(stmt); 

的时候统一提交,而上面的代码使用的临时变量,rc = sqlite3_step(stmt);的时候,早就不存在了。因此乱码也是正常的。

修改如下:

sqlite3_stmt *stmt;
 CString sql = "insert into work values (";
 int rc = sqlite3_prepare_v2(db, sql.GetString(), -1, &stmt, NULL);

 if(rc != SQLITE_OK)
 {
 MessageBox("sqlite3_prepare_v2 Failed!");
 return;
 }

 count = 0;
 p_wnd = PrevWnd;

 CString DbStr[ID_TOTALCOUNT + 1];

 while(count++ < ID_TOTALCOUNT)
 {
 DbStr[count].Empty();
 
 p_wnd = CWnd::GetNextDlgTabItem(p_wnd, FALSE); 
 if(p_wnd == NULL)
 {
  return;
 }

 p_wnd->GetWindowText(DbStr[count]);

 do
 {
  if(!DbStr[count].GetLength())
  {
  rc = sqlite3_bind_null(stmt, count);
  break;
  }

  //日期相关
  if( count == ID_CHUDANRIQI || 
  count == ID_CHUFARIQI || 
  count == ID_HUANKUANRIQI || 
  count == ID_HUOLIRIQI)
  {
  CDateTimeCtrl *TimeCtl = (CDateTimeCtrl *)p_wnd;  
  CString time = DateTimeToString(*TimeCtl);

  DbStr[count] = time;

  rc = sqlite3_bind_text(stmt, count, time.GetString(), time.GetLength(), SQLITE_STATIC);
  }
  else
  {
  //金钱相关的处理real类型
  if( count == ID_BAOXIANJINE || 
   count == ID_YONGJINBILV || 
   count == ID_JINGBAOFEI || 
   count == ID_HUANKUANJINE || 
   count == ID_LIRUNBILV || 
   count == ID_LIRUNJINE)
  {
   double tMoney = 0.0;
   int rtn = sscanf_s(DbStr[count].GetString(), "%lf", &tMoney);

   ASSERT(rtn == 1);

   rc = sqlite3_bind_double(stmt, count, tMoney);
  }
  else
  {
   rc = sqlite3_bind_text(stmt, count, DbStr[count].GetString(), DbStr[count].GetLength(), SQLITE_STATIC);
  }
  }
 }while(0);

 if(rc != SQLITE_OK)
 {
  CString ErrStr = sqlite3_errstr(rc);
  MessageBox(ErrStr);

  return;
 }
 }

 rc = sqlite3_step(stmt); 

 if(rc != SQLITE_DONE)
 {
 if(rc == SQLITE_ERROR)
 {
  CString DbErr;
  DbErr.Format("Sql Insert failed, %s", sqlite3_errmsg(db));

  MessageBox(DbErr);
 }
 else
 {
  MessageBox("sqlite3_step Failed!");
 } 
 }

 sqlite3_finalize(stmt);

附上数据库创建的sql语法:

sqlite> .dump work
PRAGMA foreign_keys=OFF;
BEGIN TRANSACTION;
CREATE TABLE work (baodanhao text unique primary key , chudanriqi text,qudao text,lianxiren text,xiaoshou text,beibaorenxingming text,chufar
iqi text,baoxianpinpai text,baoxianjihua text,baoxianjine real,yongjinbilv real,jingbaofei real,huankuanfangshi text,haikuanjine real,huanku
anriqi text,shifouquane text,lirunbilv real,lirunjine real,huoliriqi text,fapiaojisong text,shifubaoxiangongsi text,beizhu text);

总结

以上就是这篇文章的全部内容了,希望本文的内容对大家的学习或者工作能带来一定的帮助,如果有疑问大家可以留言交流,谢谢大家对的支持。

一句话新闻
一文看懂荣耀MagicBook Pro 16
荣耀猎人回归!七大亮点看懂不只是轻薄本,更是游戏本的MagicBook Pro 16.
人们对于笔记本电脑有一个固有印象:要么轻薄但性能一般,要么性能强劲但笨重臃肿。然而,今年荣耀新推出的MagicBook Pro 16刷新了人们的认知——发布会上,荣耀宣布猎人游戏本正式回归,称其继承了荣耀 HUNTER 基因,并自信地为其打出“轻薄本,更是游戏本”的口号。
众所周知,寻求轻薄本的用户普遍更看重便携性、外观造型、静谧性和打字办公等用机体验,而寻求游戏本的用户则普遍更看重硬件配置、性能释放等硬核指标。把两个看似难以相干的产品融合到一起,我们不禁对它产生了强烈的好奇:作为代表荣耀猎人游戏本的跨界新物种,它究竟做了哪些平衡以兼顾不同人群的各类需求呢?