JAVA 개발에 있어 JDBC의 운용에 대한 심층적인 설명-java지도 시간-php.cn

JAVA 개발에 있어 JDBC의 운용에 대한 심층적인 설명

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풀어 주다： 2018-07-20 10:42:36

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1326명이 탐색했습니다.

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jdbc 작업 프로세스를 제공합니다. 1. Jar 패키지 가져오기; 기록된 수업(예: 학생 수업) 3. 연결 획득 4. SQL 실행.

// sql的执行 
// insert
private static int insert(Student student) {
    Connection conn = getConn();
    int i = 0;
    String sql = "insert into students (Name,Sex,Age) values(?,?,?)";
    PreparedStatement pstmt;
    try {
        pstmt = (PreparedStatement) conn.prepareStatement(sql);
        pstmt.setString(1, student.getName());
        pstmt.setString(2, student.getSex());
        pstmt.setString(3, student.getAge());
        i = pstmt.executeUpdate();
        pstmt.close();
        conn.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }
    return i;
}

// update
private static int update(Student student) {
    Connection conn = getConn();
    int i = 0;
    String sql = "update students set Age=&#39;" + student.getAge() + "&#39; where Name=&#39;" + student.getName() + "&#39;";
    PreparedStatement pstmt;
    try {
        pstmt = (PreparedStatement) conn.prepareStatement(sql);
        i = pstmt.executeUpdate();
        System.out.println("resutl: " + i);
        pstmt.close();
        conn.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }
    return i;
}
// select xx from tableName
private static Integer getAll() {
    Connection conn = getConn();
    String sql = "select * from students";
    PreparedStatement pstmt;
    try {
        pstmt = (PreparedStatement)conn.prepareStatement(sql);
        ResultSet rs = pstmt.executeQuery();
        int col = rs.getMetaData().getColumnCount();
        System.out.println("============================");
        while (rs.next()) {
            for (int i = 1; i <= col; i++) {
                System.out.print(rs.getString(i) + "\t");
                if ((i == 2) && (rs.getString(i).length() < 8)) {
                    System.out.print("\t");
                }
             }
            System.out.println("");
        }
            System.out.println("============================");
    } catch (SQLException e) {
        e.printStackTrace();
    }
    return null;
}

// delete
private static int delete(String name) {
    Connection conn = getConn();
    int i = 0;
    String sql = "delete from students where Name=&#39;" + name + "&#39;";
    PreparedStatement pstmt;
    try {
        pstmt = (PreparedStatement) conn.prepareStatement(sql);
        i = pstmt.executeUpdate();
        System.out.println("resutl: " + i);
        pstmt.close();
        conn.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }
    return i;
}

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테스트:

// 测试
public static void main(String args[]) {
    JDBCOperation.getAll();
    JDBCOperation.insert(new Student("Achilles", "Male", "14"));
    JDBCOperation.getAll();
    JDBCOperation.update(new Student("Bean", "", "7"));
    JDBCOperation.delete("Achilles");
    JDBCOperation.getAll();
}

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출력 결과:

============================
1    Ender        male    8    
2    Bean        male    6    
3    Petra        fema    9    
4    Peter        male    9    
5    _Graff        male    40    
6    GOD        fema    255    
============================
============================
1    Ender        male    8    
2    Bean        male    6    
3    Petra        fema    9    
4    Peter        male    9    
5    _Graff        male    40    
6    GOD        fema    255    
7    Achilles    Male    14    
============================
resutl: 1
resutl: 1
============================
1    Ender        male    8    
2    Bean        male    7    
3    Petra        fema    9    
4    Peter        male    9    
5    _Graff        male    40    
6    GOD        fema    255    
============================

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