Question

我一直在研究一个与mysql数据库连接的java应用程序。我可以连接并运行查询，但是当我尝试获取字符串并将其作为sql查询运行时，我收到此错误。

Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'INSERT INTO usageData (`COMID`,`Year`,`Month`,`kwhr`,`co2`) 
VALUES ('15650', '2' at line 3
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
at com.mysql.jdbc.Util.getInstance(Util.java:384)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1054)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3566)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3498)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1959)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2113)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2562)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1664)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1583)

Bellow是我用来连接数据库的代码

public static void main(String[] args) throws Exception {

    String dbms = "mysql";
    String serverName = "localhost";
    String portNumber = "8889";
    String DBName = "ConnectDatabase";
    String user = "root";
    String password = "root";

    ArrayList<Integer> yearList = new ArrayList<Integer>();
    ArrayList<CustomerRecord> customerRecordList = getCustomerRecords(args[0], yearList);
    ArrayList<ClimateRecord> climateRecordList = getClimateRecords(args[1]);


    StringBuffer buf = new StringBuffer();

    for (CustomerRecord record : customerRecordList) {
        buf.append(customerRecord2SQL(record));
    }

    for (int i = (climateRecordList.size() - 1); i >= 0; i--) {
        //for (ClimateRecord record : climateRecordList) {
        ClimateRecord record = climateRecordList.get(i);
        buf.append(climateRecord2SQL(record));
    }

    buf.append(cityStats(dbms,serverName,portNumber,DBName,user,password));
    buf.append(zipStats(dbms,serverName,portNumber,DBName,user,password));

    System.out.println(buf.toString());

    //here is the code to go ahead and update the database
    Connection con = null;

    con = DriverManager.getConnection("jdbc:" + dbms + "://" + serverName + ":" + portNumber + "/" + DBName + "?user="+user+"&password=" + password);

    Statement stmt = con.createStatement();

    stmt.executeUpdate(buf.toString());

    BufferedWriter out = new BufferedWriter(new FileWriter(args[2]));
    out.write(buf.toString());
    out.close();
}

Answer 1

这不是连接问题。这意味着您的SQL语句出了问题。尝试按原样复制语句并直接在数据库中执行。查看错误，然后在Java代码中更正它。

我注意到字段名称周围的单引号看起来很奇特。这可能是个问题。

Answer 2

这是发生的事情，以及其他人未能意识到的事情。我一次尝试运行包含在字符串缓冲区中的数百万个查询时，JDBC不会执行多个查询。

Answer 3

您的查询应为'INSERT INTO usageData VALUES（COMID，Year，Month，kwhr，co2）; 和btw COMID，一年......这些是什么.. ??为什么花哨的报价...... ??

Jdbc和MySql不想一起玩得很好

3 个答案: