Question

我正在使用jdbc创建一些数据库表。在其中一个表中，我收到此错误消息：TYPE 'MEET' does not exist.。有什么想法吗？

代码如下：

public class MeetingDAO {
public static String getTableString(){
    String meetingTable =   "create table project ( " +
                            "meeting_id integer not null, " +
                            "timestamp meet, " +
                            "project_key varchar(10), " +
                            "primary key(meeting_id))";
    return projectTable;        
  }
}

public class JDBCUtil {
private static  final String dbURL= "jdbc:derby:MyDB;create=true;";
private static final String userID = "moon";
private static final String password = "moonmoon";

public static void init(){
    makeTable(MeetingDAO.getTableString());
}

private static void makeTable(String tableSQL){
    Connection conn = null;
    try {
        conn = JDBCUtil.getConnection();
        Statement stmt = null;
        try {
            stmt = conn.createStatement();
            stmt.executeUpdate(tableSQL);
        }
        finally {
            JDBCUtil.closeStatement(stmt);
        }
        JDBCUtil.commit(conn);
    }
    catch (SQLException e) {
        System.out.println(e.getMessage());
        JDBCUtil.rollback(conn);
    }
    finally {
        JDBCUtil.closeConnection(conn);
    }

}

public static Connection getConnection() throws SQLException{
    Driver derbyEmbededDriver = new EmbeddedDriver();
    DriverManager.registerDriver(derbyEmbededDriver);

    Connection conn = DriverManager.getConnection(dbURL, userID, password);

    conn.setAutoCommit(false);  

    return conn;
}

public static void closeConnection(Connection conn){
    try{
        if(conn != null)
            conn.close();
    }
    catch(SQLException e){
        e.printStackTrace();
    }
}

public static void closeStatement(Statement stmt){
    try {
        if(stmt != null)
            stmt.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

public static void closeResultSet(ResultSet rs){
    try {
        if(rs != null)
            rs.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

public static void commit(Connection conn){
    try {
        if(conn != null)
            conn.commit();
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

public static void rollback (Connection conn){
    try {
        if(conn != null)
            conn.rollback();
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

}

Answer 1

只需交换这两个词：

timestamp meet

到

meet timestamp

首先是列命名，然后是列数据表。

Answer 2

您混合了列meet的列名和数据类型。

public class MeetingDAO {
public static String getTableString(){
    String meetingTable =   "create table project ( " +
                            "meeting_id integer not null, " +
                            "meet timestamp, " +
                            "project_key varchar(10), " +
                            "primary key(meeting_id))";
    return projectTable;        
  }
}

输入＆＃34; ...＆＃34;不存在 - JDBC错误

2 个答案: