在线考试系统（六）——javaDao

太过爱你忘了你带给我的痛 2023-06-17 05:58 118阅读 0赞

### 在线考试系统（六）——javaDao ###

*   *   *  前言
         *  项目结构
         *  teacherDao

### 前言 ###

对于基本的sql 的增删改查通过代码自己生成

#include <bits/stdc++.h>
    using namespace std;
    
    string tolower(string &s)
    { 
        string str = "";
        for (int i = 0; i < s.size(); ++i)
            str += s[i];
        str[0] -= 32;
        return str;
    }
    
    int main()
    { 
        fileopen("in.txt", "t", stdin);
        string s, table;
        cin >> table;
        vector<string> field;
        while (cin >> s)
            field.push_back(s);
        cout << "String sql = \" select * from " + table + " where " + field[0] + "='\"+id+\"';\";\n";
        cout << endl;
        cout << "String sql = \" insert into " + table + " (";
        for (int i = 0; i < field.size(); ++i)
        { 
            if (i != field.size() - 1)
            { 
                cout << field[i] << " , ";
            }
            else
            { 
                cout << field[i] << " ) values ( \";\n";
            }
        }
        for (int i = 0; i < field.size(); ++i)
        { 
            if (i != field.size() - 1)
            { 
                cout << "sql +=\" '\" +" + table + ".get" << tolower(field[i]) << "()+ \"' , \";\n";
            }
            else
            { 
                cout << "sql +=\" '\" +" + table + ".get" << tolower(field[i]) << "()+ \"' ); \";\n";
            }
        }
        cout << endl;
        cout << "String sql = \" insert into " + table + " (";
        for (int i = 1; i < field.size(); ++i)
        { 
            if (i != field.size() - 1)
            { 
                cout << field[i] << " , ";
            }
            else
            { 
                cout << field[i] << " ) values ( \";\n";
            }
        }
        for (int i = 1; i < field.size(); ++i)
        { 
            if (i != field.size() - 1)
            { 
                cout << "sql +=\" '\" +" + table + ".get" << tolower(field[i]) << "()+ \"' , \";\n";
            }
            else
            { 
                cout << "sql +=\" '\" +" + table + ".get" << tolower(field[i]) << "()+ \"' ); \";\n";
            }
        }
        cout << endl;
        cout << "String sql =\" update " + table + " set \" ;\n";
        for (int i = 1; i < field.size(); ++i)
        { 
            if (i != field.size() - 1)
            { 
                cout << "sql += \" " + field[i] << "='\"+" << table << ".get" << tolower(field[i]) << "()+\"',\";\n";
            }
            else
            { 
                cout << "sql += \" " + field[i] << "='\"+" << table << ".get" << tolower(field[i]) << "()+\"' \";\n";
            }
        }
        cout << "sql += \" where " + field[0] << "='\"+" << table << ".get" << tolower(field[0]) << "()+\"';\";\n";
        cout << endl;
        cout << "String sql =\" delete from " + table + " where " + field[0] + "='\" +id + \"';\"; ";
        cout << endl;
    }

输入案例

teacher teacherid name pwd email  phone sex dob

### 项目结构 ###

![在这里插入图片描述][20191127195634555.jpg]

### teacherDao ###

package pers.ant.oe.dao;
    
    import java.sql.Connection;
    import java.sql.ResultSet;
    import java.sql.Statement;
    import java.util.ArrayList;
    import java.util.List;
    
    import pers.ant.oe.bean.teacherBean;
    import pers.ant.oe.jdbc.jdbc;
    
    public class teacherDao { 
    	public static void add(teacherBean teacher) { 
    		String sql =  " insert into teacher (teacherid , name , pwd , email , phone , sex , dob ) values ( ";
    		sql +=" '" +teacher.getTeacherid()+ "' , ";
    		sql +=" '" +teacher.getName()+ "' , ";
    		sql +=" '" +teacher.getPwd()+ "' , ";
    		sql +=" '" +teacher.getEmail()+ "' , ";
    		sql +=" '" +teacher.getPhone()+ "' , ";
    		sql +=" '" +teacher.getSex()+ "' , ";
    		sql +=" '" +teacher.getDob()+ "' ); ";
    		AUD(sql);
    	}
    
    	public static void update(teacherBean teacher) { 
    		String sql =" update teacher set " ;
    		sql += " name='"+teacher.getName()+"',";
    		sql += " pwd='"+teacher.getPwd()+"',";
    		sql += " email='"+teacher.getEmail()+"',";
    		sql += " phone='"+teacher.getPhone()+"',";
    		sql += " sex='"+teacher.getSex()+"',";
    		sql += " dob='"+teacher.getDob()+"' ";
    		sql += " where teacherid='"+teacher.getTeacherid()+"';";
    		AUD(sql);
    	}
    
    	public static void delete(int id) { 
    		String sql  =" delete from teacher where teacherid='" +id + "';"; 
    		AUD(sql);
    	}
    	
    	public static void AUD(String sql) { 
    		Connection connection = jdbc.getConn();
    		Statement statement = null;
    		try { 
    			statement = connection.createStatement();
    			statement.executeUpdate(sql);
    		} catch (Exception e) { 
    			e.printStackTrace();
    		} finally { 
    			jdbc.close(connection, statement, null);
    		}
    	}
    	
    	public static List<teacherBean> select(String sql) { 
    		List <teacherBean> list = new ArrayList<>();
    		Connection connection = jdbc.getConn();
    		Statement statement = null;
    		ResultSet resultSet = null;
    		teacherBean teacher = new teacherBean();
    		try { 
    			statement = connection.createStatement();
    			resultSet = statement.executeQuery(sql);
    			while(resultSet.next()){ 
    				// teacherid name pwd email phone sex dob
    				teacher.setTeacherid(resultSet.getInt(1));
    				teacher.setName(resultSet.getString(2));
    				teacher.setPwd(resultSet.getString(3));
    				teacher.setEmail(resultSet.getString(4));
    				teacher.setPhone(resultSet.getString(5));
    				teacher.setSex(resultSet.getString(6));
    				teacher.setDob(resultSet.getString(7));
    				list.add(teacher);
    			}
    		} catch (Exception e) { 
    			e.printStackTrace();
    		} finally { 
    			jdbc.close(connection, statement, null);
    		}
    		return list;
    	}
    }

根据需要后面可以添加

[20191127195634555.jpg]: https://img-blog.csdnimg.cn/20191127195634555.jpg