Question

我正在研究Node.js版本v0.12.7
我的目标是将Question_ID数组输入Postgres数据库问题无法将json数组传递给Postgres函数
不好的解决方案在最坏的情况下，我会逐个查询 我的尝试是转换question_id的输入数组，例如：
从数组[2,4,1,3]
致JSON：[{order：1，question_id：2}，{order：2，question_id：4}，{order：3，question_id：1}，{order：3，question_id：3}]

然后将其传递给pg。

我通过exports.IntArray2JSON函数成功将整数数组转换为JSON数组。

exports.IntArray2JSON = function(req){
    return new Promise(function(fulfill,reject){
    var arr = [];
    var in_array = req.body.questionlist;
    for(var i = 1 ; i <= in_array.length ; i++){
        var data = {order : i, question_id : in_array[i-1]};
        arr.push(data);
    }
    fulfill(arr);
    });
};

之后。我将对象数组进行字符串化。和JSON.parse（）它简而言之，我将它们命名为var a和var b 不幸的是，a和b都不起作用。当我在数据数组中使用它时
Console.log＆＃39; a＆＃39;情况下：

pg receive : 
[ 8,
  '[{"order":1,"question_id":5},{"order":2,"question_id":2},{"order":3,"question_id":3},{"order":4,"question_id":1}]' ]

＆＃39; a＆＃39;错误案例：

{ [error: cannot begin/end transactions in PL/pgSQL]
  name: 'error',
  length: 235,
  severity: 'ERROR',
  code: '0A000',
  detail: undefined,
  hint: 'Use a BEGIN block with an EXCEPTION clause instead.',
  position: undefined,
  internalPosition: undefined,
  internalQuery: undefined,
  where: 'PL/pgSQL function dugong.quizquestion_jsadd(integer,json) line 20 at SQL statement',
  schema: undefined,
  table: undefined,
  column: undefined,
  dataType: undefined,
  constraint: undefined,
  file: 'pl_exec.c',
  line: '3377',
  routine: 'exec_stmt_execsql' }

尝试＆＃39; b＆＃39;案件： Console.log的＆＃39; b＆＃39;情况下：

pg receive : 
[ 8,
  [ { order: 1, question_id: 5 },
    { order: 2, question_id: 2 },
    { order: 3, question_id: 3 },
    { order: 4, question_id: 1 } ] ]

＆＃39; b＆＃39;错误案例：

{ [error: invalid input syntax for type json]
  name: 'error',
  length: 178,
  severity: 'ERROR',
  code: '22P02',
  detail: 'Expected ":", but found ",".',
  hint: undefined,
  position: undefined,
  internalPosition: undefined,
  internalQuery: undefined,
  where: 'JSON data, line 1: {"{\\"order\\":1,\\"question_id\\":5}",...',
  schema: undefined,
  table: undefined,
  column: undefined,
  dataType: undefined,
  constraint: undefined,
  file: 'json.c',
  line: '1136',
  routine: 'report_parse_error' }

这是节点中的功能。

exports.postQuizQuestion = function(client,req){
    console.log('coming in function');
    exports.test = function(array,callback){
    console.log('hello in test function');
    console.log(array);
    for(var i = 0 ; i < array.length ; i++){
        console.log(typeof(array[i]));
        if(i == array.length -1){
        callback(array);
        }
    }
    };
    exports.test2 = function(array,callback){
    var a = JSON.stringify(req.body.questionlist2);
    var b = JSON.parse(a);

    var data = [req.body.quizid, b];
    console.log('pg receive : ');
    console.log(data);
    var qstr = "SELECT Dugong.QuizQuestion_JsAdd($1,$2)";
    var questList = client.query(qstr, data, function(er,result){
            if(er){
        console.log(er);
        var data = pgdown.rreject(er,req.params.quizid);
        callback();
        return;
            }
        console.log('QuizQuestion table updated');
        callback();
    });
    };
    exports.test(req.body.questionlist2, function(array){
    exports.test2(array, function(){
        console.log('end of the function');
    });
    });
};

这是表结构。

CREATE TABLE Dugong.QuizQuestion(
        Quiz_ID int,
        Order_question int,
        Question_ID int,        --FK
        LastModified timestamp with time zone default current_timestamp,
        PRIMARY KEY(Order_question,Quiz_ID),
        FOREIGN KEY(Question_ID) REFERENCES Dugong.Question(Question_ID) ON DELETE RESTRICT     ,       
        CONSTRAINT QzID_QID UNIQUE (Quiz_ID, Question_ID)
);

我的pg功能：

CREATE OR REPLACE FUNCTION Dugong.QuizQuestion_JsAdd(
       in_quiz_id int,
       in_question_id_list json
)
RETURNS boolean AS $$
DECLARE
        idx integer;
        i json;
BEGIN
        idx := 1;
        FOR i IN SELECT * FROM json_array_elements(in_question_id_list)
        LOOP
                RAISE NOTICE '%', idx;
                PERFORM Dugong.QuizQuestion_Add(in_quiz_id, idx, i->>question_id);
                idx := idx + 1;
        END LOOP;

        RETURN true;

EXCEPTION WHEN others THEN
        RAISE NOTICE 'The transaction is in an uncommitable state.'
                                                        'Transaction was rolled back.';
        RAISE NOTICE '% %', SQLERRM, SQLSTATE;
        ROLLBACK;
END;
$$ LANGUAGE PLPGSQL;

将JSON数组传递给postgres而不使用双反斜杠

0 个答案: