Question

我想一次在数据库中插入单个数据，但在数据库中一次生成重复行。

-----------------------------
Output(in mysql table=privilege)
----------------------------- 
id privilege
1  abc
2  abc

以下是我插入数据的方法：

public int addPrivilege(String privilege) {
    PreparedStatement preparedStatement = null;
    String sqlprivilege;
    Connection dbConnection = null;
    int pinsert = 0;
    try {
        sqlprivilege = "insert into privilege(privilege) values(?)";
        dbConnection = ConnectionDao.getDBConnection();
        preparedStatement = dbConnection.prepareStatement(sqlprivilege);
        preparedStatement.setString(1, privilege);
        pinsert = preparedStatement.executeUpdate();
        if(preparedStatement.executeUpdate()==1)
            pinsert=1;
        else
            pinsert=0;
        System.out.println("privilege is add and name is:- " +privilege);
    } catch (SQLException e) {

        System.out.println(e.getMessage());

    } finally {

        if (preparedStatement != null) {
            try {
                preparedStatement.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        if (dbConnection != null) {
            try {
                dbConnection.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

    }
    return pinsert;
}

Answer 1

在代码中执行两次sql。

1) pinsert = preparedStatement.executeUpdate();
2) if(preparedStatement.executeUpdate()==1)

我不确定executeUpdate的返回值。但我认为第一个就足够了，不需要检查返回值。如果你需要再与pinsert进行比较而不是executeupdate（再次）。

if(pinsert == 1)

Answer 2

你正在使用两次executeUpdate（）;如果

，删除执行哪一个

    public int addPrivilege(String privilege) {
    PreparedStatement preparedStatement = null;
    String sqlprivilege;
    Connection dbConnection = null;
    int pinsert = 0;
    try {
        sqlprivilege = "insert into privilege(privilege) values(?)";
        dbConnection = ConnectionDao.getDBConnection();
        preparedStatement = dbConnection.prepareStatement(sqlprivilege);
        preparedStatement.setString(1, privilege);
        pinsert = preparedStatement.executeUpdate();
        //try this
        if(pinsert ==1)
            pinsert=1;
        else
            pinsert=0;
        System.out.println("privilege is add and name is:- " +privilege);
    } catch (SQLException e) {

        System.out.println(e.getMessage());

    } finally {

        if (preparedStatement != null) {
            try {
                preparedStatement.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        if (dbConnection != null) {
            try {
                dbConnection.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

    }
    return pinsert;
}

在数据库中插入单个数据，但在插入时也添加了数据库中的重复行

2 个答案: