Question

我在尝试将值插入数据库时遇到问题。

当我执行下面的代码时，它可以正常工作

insertString = "insert into Players     
values(1,'Fred','Fish','fredfish@gamer.net','Ithroeann',19770322)";
statement.executeUpdate(insertString);

但是当我尝试这样做时，在这里它会给我一个不正确的语法＆＃39; 0＆＃39;错误

我试图将其循环以通过文件自动添加

Scanner input = new Scanner(new File("players.txt"));
        while (input.hasNext()) {
        String[] temp;
        String str = input.next();
            temp = str.split("\\|");

insertString = "insert into Players values(temp[0], temp[1],temp[2],temp[3],temp[4],temp[5])";
        statement.executeUpdate(insertString);
}

Answer 1

这是一个字符串。如果要将临时数组的元素附加到String，则不能这样做。

你可以这样做：

insertString = "insert into Players values("+temp[0]+",'"+temp[1]+"','"+temp[2]+"','"+temp[3]+"','"+temp[4]+"',"+temp[5]+")";
statement.executeUpdate(insertString);

当然使用PreparedStatement会是一个更好的解决方案。

PreparedStatement stmt = conn.prepareStatement("insert into Players values(?,?,?,?,?,?)");
stmt.setInt (1, Integer.parseInt(temp[0]));
stmt.setString (2, temp[1]);
stmt.setString (3, temp[2]); 
stmt.setString (4, temp[3]); 
stmt.setString (5, temp[4]);
stmt.setInt (6, Integer.parseInt(temp[5]));
stmt.executeUpdate();

Answer 2

使用PreparedStatement将查询参数绑定为

PreparedStatement pStmt = connection.prepareStatement(
       "insert into Players values (?, ?, ?, ?, ?, ?)");

// index starts from 1
int i = 1;
// bind first int value
pStmt.setInt(i, Integer.parseInt(temp[0]));

// bind string values
for (; i < temp.length; i++)
    pStmt.setString(i, temp[i-1]);

// bind last int value
pStmt.setInt(i, Integer.parseInt(temp[i-1]));

// execute insert
pStmt.executeUpdate();

Answer 3

除非上面发布的代码是部分代码，否则您似乎错过了语句准备部分。尝试以下内容：

Scanner input = new Scanner(new File("players.txt"));
        while (input.hasNext()) {
        String[] temp;
        String str = input.next();
            temp = str.split("\\|");

dbConnection = getDBConnection(); // Implement this method based on your DB configuration

String insertString = "insert into Players values(?, ?, ? , ?, ?, ?)";

PreparedStatement statement = dbConnection.createStatement();
statement.setInt(temp[0]); // int, or whichever type you have
statement.setInt(temp[1]); // int, or whichever type you have
statement.setInt(temp[2]); // int, or whichever type you have
statement.setInt(temp[3]); // int, or whichever type you have
statement.setInt(temp[4]); // int, or whichever type you have
// ^ for the above, if all fields are the same - you can do this in a loop


statement.executeUpdate(insertTableSQL); // execute the insert

Java“0”附近的语法不正确

3 个答案: