嘗試從jtable刪除Java SQL語法錯誤

我試圖從jtable和數據庫一起刪除選定的行，但我收到語法錯誤。可能是因爲我使用varchar或真的在這種情況下語法是錯誤的？嘗試從jtable刪除Java SQL語法錯誤

btnNewButton_2 = new JButton("Dzēst"); 
    btnNewButton_2.addActionListener(new ActionListener() { 
     public void actionPerformed(ActionEvent e) { 
      Statement statement = null; 
      try { 
       int tableRow = table_1.getSelectedRow(); 
       Object Kods = table_1.getValueAt(tableRow, 0); 
       Object Nosaukums = table_1.getValueAt(tableRow, 1); 
       Object Inventara = table_1.getValueAt(tableRow, 2); 
       Object Uzskaites = table_1.getValueAt(tableRow, 3); 
       Object Iegad = table_1.getValueAt(tableRow, 4); 
       Statement stmt = null; 
       Connection connection = ConnectDB(); 


       String sql = "DELETE FROM users " + 
         "WHERE Kods = " + Kods + " AND Nosaukums = '" + Nosaukums + "' AND Inventara Nr = " + 
         Inventara + " AND Uzskaites vertiba = '" + Uzskaites + "' AND Iegades vertiba = " + Iegad; 
       stmt = connection.createStatement(); 
       stmt.executeUpdate(sql); 

      } catch (SQLException ex) { 
       Logger.getLogger(dddddddd.class.getName()).log(Level.SEVERE, null, ex); 
        JOptionPane.showMessageDialog(null, "Nav ievadita visa informacija"); 
      }

錯誤：

You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'Nr = ttttt AND Uzskaites vertiba = '3.0' AND Iegades vertiba = 3.0' at line 1

數據庫變量：

Kods -Index -int(255)  
Nosaukums - varchar(255)   
Inventara Nr - varchar(255) 
Uzskaites vertiba - float     
Iegades vertiba - float

來源

2017-10-14 Krichukzz

我還建議你看一下'PreparedStatement's – MadProgrammer

請注意，您的列具有空間分隔的名字。通常使用這種命名約定並不是最佳實踐，但是使用snake_case或CamelCase。

就你而言，你需要正確地引用你的列名，例如

WHERE `Inventara Nr` = '33'

請注意，儘管您的代碼易受SQL注入攻擊。我建議閱讀有關它們。您應該始終使用PreparedStatements。

來源

2017-10-14 22:16:28 petul

謝謝，會記住。用snake_case改變了一切，但現在有新的錯誤。「where子句」中的未知列'ttetetetete'。 – Krichukzz

@Krichukzz所有的字符都必須放在引號中。示例：刪除文檔WHERE content ='Hello World'。但是如前所述，PreparedStatements將爲您的參數使用setString時爲您做到這一點。在你的情況'Inventara Nr'確實是一個varchar，所以它應該在''Inventara Nr'='ttetetetetete'。這可以幫助你使用PreparedStatements：http://docs.oracle.com/javase/tutorial/jdbc/basics/prepared.html – petul

'String sql =「DELETE FROM users」+ \t \t「WHERE Kods =」+ Kods + 「ANDNosaukums ='」+ Nosaukums +「'AND Inventara_Nr ='」+ \t \t Inventara +「'AND Uzskaites_vertiba =」+ Uzskaites +「AND Iegades_vertiba =」+ Iegad; \t \t stmt = connection.createStatement（）; \t \t stmt.executeUpdate（sql）; '仍然不想刪除任何東西。即使我把'Nosaukums'和'Inventara_Nr'設置爲quoutes。 – Krichukzz

嘗試從jtable刪除Java SQL語法錯誤

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