C++Builder关于SQL的一个简单的查询问题

[yangtou1]

一个简单的查询，运行时提示：参数不足，期待是1。不知道问题在哪？代码如下
int num;
num = StrToInt(Edit1->Text);
Query1->Close();
Query1->SQL->Clear();
Query1->SQL->Add("SELECT * FROM 教师表 WHERE 教师编号 = num");
Query1->Prepare();
Query1->Active = True;

期望大家给点意见！

[new_bird_0001]

Query1->Close();
Query1->SQL->Clear();
Query1->SQL->Add("SELECT * FROM 教师表 WHERE 教师编号 = :num");
Query1->Prepare();
Query1->ParamByName("num")->AsInteger = StrToInt(Edit1->Text);
Query1->Active = True;

[zzbinfo]

你的sql语句写错了,

int num;
num = StrToInt(Edit1->Text);
Query1->Close();
Query1->SQL->Clear();
Query1->SQL->Add("SELECT * FROM 教师表 WHERE 教师编号 =:num");
Query1->Params->Items[0]->AsInteger = num;
Query1->Prepare();
Query1->Active = true;

[cankoo]

//forum.csdn.net/PointForum/ui/scripts/csdn/Plugin/001/face/42.gif][/img]

[ccrun.com]

int num;
num = StrToInt(Edit1->Text);
Query1->Close();
Query1->SQL->Clear();
Query1->SQL->Add(String().sprintf("SELECT * FROM 教师表 WHERE 教师编号=%d", num));
Query1->Prepare();
Query1->Active = True;

[stbigcrab]

int num;
num = StrToInt(Edit1->Text);
Query1->Close();
Query1->SQL->Clear();
Query1->SQL->Add("SELECT * FROM 教师表 WHERE 教师编号 = " + IntToStr(num));
Query1->Open();

或者
Query1->Close();
Query1->SQL->Clear();
Query1->SQL->Add("SELECT * FROM 教师表 WHERE 教师编号 = " + Edit1->Text);
Query1->Open();

:)偷偷蹭点分。

[netying]

Query1->SQL->Add("SELECT * FROM 教师表 WHERE 教师编号 ="+ num);

[netying]

上边马虎了，应该是：
Query1->SQL->Add("SELECT * FROM 教师表 WHERE 教师编号 ="+ String(num));

[ssypas]

[Quote=引用 7 楼 stbigcrab 的回复:]
int num;
num = StrToInt(Edit1->Text);
Query1->Close();
Query1->SQL->Clear();
Query1->SQL->Add("SELECT * FROM 教师表 WHERE 教师编号 = " + IntToStr(num));
Query1->Open();

或者
Query1->Close();
Query1->……
[/Quote]

正解

[半夜回家]

int num;
try{
num = StrToInt(Edit1->Text);
}
catch(...){
ShowMessage("数字不合法！");
return;
}
Query1->Close();
Query1->SQL->Clear();
Query1->SQL->Add("SELECT * FROM 教师表 WHERE 教师编号 = " + QuotedStr(Edit1->Text));
Query1->Open();

[七擒关羽]

//int num;
//num = StrToInt(Edit1->Text);//不需要重复转换
Query1->Close();
Query1->SQL->Clear();
Query1->SQL->Add("SELECT * FROM 教师表 WHERE 教师编号=" +Edit1->Text);
Query1->Prepare();
Query1->Open();//查询用open

[royallii]

[Quote=引用 7 楼 stbigcrab 的回复:]
int num;
num = StrToInt(Edit1->Text);
Query1->Close();
Query1->SQL->Clear();
Query1->SQL->Add("SELECT * FROM 教师表 WHERE 教师编号 = " + IntToStr(num));
Query1->Open();

或者
Query1->Close();
Query1->……
[/Quote]

Right

[royallii]

active=true没有试过，但是查询用open肯定错不了。