Question

当用户创建注释时，Mongoose API会创建一个文档，其中包含用户注释的值，然后仅使用默认参数创建其他文档。有没有办法从数据库中删除它？

我的Note架构是这样的：

var NoteSchema = new mongoose.Schema({
    title: String,
    text: String,
    color: {
        type: String,
        default: "white", <--- default
    }
    favorited: {
        type: Boolean,
        default: false,   <--- default
    }
});

在mongo控制台中：

// Document it creates and what I expect
{ 
    "_id": "58795af461e2db2db804997d", 
    "title" : "Testing: Hello", 
    "favorited" : false, 
    "color": "strawberry", 
    "author": { 
        "id": "587950df61e2db2db8049972", 
        "username" : "tester" 
    } 
}
// Additional default (unneccessary) document created:  
{ 
    "_id": "58795af461e2db2db804997e", 
    "favorited": false, <--- from the Schema
    "color": "gray" <--- from the Schema
}

从用户的角度来看，它没有做任何事情，但我不希望它为每个音符创建一个包含默认值的附加文档。我怎么能摆脱它？

Answer 1

您可以更改架构，为#include <iostream> #include <string> #include <vector> using namespace std; class my_pair { private: int m_x,m_y; public: my_pair( int x, int y ) : m_x( x ), m_y( y ) {} void swap() { int tmp = m_x; m_x = m_y; m_y = tmp; } int x() { return m_x; } int y() { return m_y; } }; int main() { // Generate some input: // I'm assuming that the tokens in the columns are // in the form 0,1,2 etc such that the tokens // themselves can be interpreted as an index of an array. // I think there is no loss of generality here, as it can // be considered a re-labeling... vector<my_pair> pair_vector; pair_vector.push_back( my_pair( 0,1 ) ); pair_vector.push_back( my_pair( 1,1 ) ); pair_vector.push_back( my_pair( 2,2 ) ); pair_vector.push_back( my_pair( 2,1 ) ); pair_vector.push_back( my_pair( 2,0 ) ); pair_vector.push_back( my_pair( 2,1 ) ); pair_vector.push_back( my_pair( 2,1 ) ); pair_vector.push_back( my_pair( 2,2 ) ); cout << "Start vector:" << endl; for( auto p : pair_vector ) cout << p.x() << ' ' << p.y() << endl; // 1: Count number of occurrences of each token. // Here the assumption on the tokens is used: vector<int> num_tokens; for( auto& p : pair_vector ) { if( p.x()+1 > num_tokens.size() ) num_tokens.resize( p.x()+1 ); num_tokens[p.x()]++; if( p.y()+1 > num_tokens.size() ) num_tokens.resize( p.y()+1 ); num_tokens[p.y()]++; } // 2. Now I iterate through the columns for each token // and swap each token // that appears more often than n/2 times in that column, // where n is the number of appearances of each token: bool swap_was_performed = true; while( swap_was_performed ) { int token = 0; swap_was_performed = false; for( auto& n : num_tokens ) // n is the number (or frequency) of tokens { int x_ctr = 0; int y_ctr = 0; // Iterating through the input columns: for( auto& p : pair_vector ) { if( p.x()==token ) // x-values (i.e. the first column) { x_ctr++; if( x_ctr>n/2 ) { p.swap(); swap_was_performed = true; } } } for( auto& p : pair_vector ) { if( p.y()==token ) // y-values... { y_ctr++; if( y_ctr>n/2 ) { p.swap(); swap_was_performed = true; } } } token++; } } cout << "After re-arranging:" << endl; for( auto p : pair_vector ) cout << p.x() << ' ' << p.y() << endl; }和required字段设置minlength和title验证。

text

这将确保如果缺少var NoteSchema = new mongoose.Schema({ title: { type: String, required: true, minlength: 15 // <--- Set the minimum title length }, text: { type: String, required: true, minlength: 100 // <--- Set the minimum text length }, color: { type: String, default: "white", } favorited: { type: Boolean, default: false, } });和/或title，则不会保存文档。此外，如果长度小于text值，则不会保存文档。

Mongoose创建附加文档以存储默认值

1 个答案: