MySQL的INSERT INTO问题

Question

这里是我的表：

CREATE TABLE IF NOT EXISTS CauHoi(MaCH VARCHAR(10) CHARACTER SET utf8 COLLATE utf8_unicode_ci PRIMARY KEY, MaMH VARCHAR(10) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL, Question TEXT CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL, Difficulty VARCHAR(10) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL, a TEXT CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL, b TEXT CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL, c TEXT CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL, d TEXT CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL, Answer VARCHAR(10) NOT NULL); 

这里是我的查询：

answerComboBox->addItem("a"); 
answerComboBox->addItem("b"); 
answerComboBox->addItem("c"); 
answerComboBox->addItem("d"); 
q.prepare("INSERT INTO CauHoi(MaCH,MaMH,Question,Difficulty,a,b,c,d,Answer) VALUES ('" 
      + maCHLineEdit->text() + "','" 
      + maMHLineEdit->text() + "','" 
      + questionTextEdit->toPlainText() + "','" 
      + difficultyComboBox->currentText()+ "','" 
      + aLineEdit->text() + "','" 
      + bLineEdit->text() + "','" 
      + cLineEdit->text() + "','" 
      + dLineEdit->text() + "'," 
      + answerComboBox->currentText()+");"); 

然而，当q.exec（），如果answerComboBox-> currentText（）==” c“，CauHoi表中的Answer列成为cLineEdit-> text（）。它是多么的疯狂！我只是希望它只是“a”，“b”，“c”，“d”。

请帮我

Answer 1

您需要添加的开始和结束的单引号括起来

answerComboBox->currentText() 

Answer 2

我找到了。我在answerComboBox-> currentText（）周围缺少单引号。