Question

我用postgresql创建一个数据库，我想连接并显示数据库。

    public Connect(){

        try {
            Class.forName("org.postgresql.Driver");
        } catch (ClassNotFoundException e) {
            System.err.println("ClassNotFoundException: Postgres Server JDBC");
        }

        try {
            conn = DriverManager.getConnection("jdbc:postgresql://localhost:5432/postgres","postgres","postgrespassword");
            System.out.println("Connection successful.");
            sql = "select * from mytable";
            stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);
            md = rs.getMetaData();
            columns = md.getColumnCount();
            for (int i = 1; i <= columns; ++i){
                columnNames.addElement(md.getCatalogName(i));
            }
            while (rs.next()){
                Vector row = new Vector(columns);
                for(int i = 0; i <= columns; ++i){
                    row.addElement(rs.getObject(i));
                }
                data.addElement(row);
            }

            rs.close();
            stmt.close();
        } catch (SQLException e){
            System.err.println("SQLException");
        }
        JTable table = new JTable(data, columnNames)
        {
            public Class getColumnClass(int column)
            {
                for (int row = 0; row < getRowCount(); row++)
                {
                    Object o = getValueAt(row, column);

                    if (o != null)
                    {
                        return o.getClass();
                    }
                }

                return Object.class;
            }
        };
        JScrollPane scrollPane = new JScrollPane( table );
        getContentPane().add( scrollPane );

        JPanel buttonPanel = new JPanel();
        getContentPane().add( buttonPanel, BorderLayout.SOUTH );
    }

    public void closeConnection() throws SQLException {
        try {
            conn.close();
            System.out.println("Connection close.");
        } catch (SQLException e) {
            System.err.println("SQLException");
        }
    }

    public void displayDatabase(){

    }
}

我得到以下异常：

org.postgresql.util.PSQLException: ERROR: syntax error at or near "mytable"
  Position: 15
    at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2157)
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1886)
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:555)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:403)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:283)
    at hu.aycm.Connect.<init>(Connect.java:37)
    at hu.aycm.Main.main(Main.java:8)

我该如何解决这个问题？有人能帮我吗？感谢

Answer 1

尝试通过在其前面加上schemaname.table_name来访问该表。

Answer 2

如果您的名称是保留名称或者表格已存在，则会发生这种情况。

让我们说你正在尝试添加一个新表，错误是： org.postgresql.util.PSQLException：错误：“mytable”或附近的语法错误

您收到此错误，因为当前架构中的postgresql已经存在mytable表或表，并且此名称已保留。

将您的表名更改为其他名称然后尝试并确保已创建表。

Java中的PostgreSQL连接 - SQLException

2 个答案: