Question

我试图创建一个程序，我可以在textarea中键入任何sql语句，然后它将执行它。如果它不是一个查询，那么只是在标签中显示受影响的行，或者如果它是一个查询，则显示结果。我知道如何使用结果集填充jtable。但我有点卡住查询与非查询部分。

Answer 1

你可能会像......一样：

package default;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Vector;

    public class DBConnector {



        private static Connection getConnection() throws SQLException
        {
            String url       = "your-url";
            String user      = "user";
            String password  = "password";

            Connection conn = DriverManager.getConnection(url, user, password);

            return conn;
        }

        public Vector<Vector<String>> ExecuteQuery(String query)
        {
            Statement stmt = null;
            ResultSet rs = null;
            //Vector of vectors for JTable
            Vector<Vector<String>> data = new Vector<Vector<String>>();
            try {
                //Create new statement
                stmt = getConnection().createStatement();
                //Execute given `query`
                rs = stmt.executeQuery(query);


                if (stmt.execute(query)) {
                    rs = stmt.getResultSet();
                }

                //while there are some rows
                while(rs.next())
                {
                    //Create new Vector
                    Vector<String> temp = new Vector<String>();
                    int numColumns = rs.getMetaData().getColumnCount();
                    //Put data into that vector
                    for ( int i = 1 ; i <= numColumns ; i++ ) {
                       temp.addElement(rs.getString(i));
                    }

                    //Add vector to `data`
                    data.add(temp);
                }

            }
            catch (SQLException ex){
                // handle any errors
                System.out.println("SQLException: " + ex.getMessage());
                System.out.println("SQLState: " + ex.getSQLState());
                System.out.println("VendorError: " + ex.getErrorCode());
            }
            finally {
                if (rs != null) {
                    try {
                        rs.close();
                    } catch (SQLException sqlEx) { }

                    rs = null;
                }

                if (stmt != null) {
                    try {
                        stmt.close();
                    } catch (SQLException sqlEx) { } // ignore

                    stmt = null;
                }
            }
            //Return
            return data;
        }
    }

首先你需要填充getConnection()个字段，然后你可以通过调用ExecuteQuery传递TextArea.getText()字符串来创建JTable，因为你会得到Vector of Vectors传递给JTable。 / p>

希望我帮助过：）

Java，TextArea用于创建SQL语句

1 个答案: