我对 TaffyDB 和 JavaScript 真的很陌生。如何在 TaffyDB 中组合方法？
我正在尝试使用distinct ()and stringify()，但它不起作用
var xyz = db().distinct("mnths").stringify ();
console.log(xyz );
我收到一条错误消息，指出stringify()不支持。
谢谢你。
问问题
626 次
1 回答
2
db().distinct("mnths")返回一个数组而不是一个 TaffyDB 对象，因此.stringify()将无法处理它。
你可以改为
JSON.stringify(db().distinct("mnths"))
| Method | Takes | Returns | Info |
|-----------------|---------------------------|-------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------|
| db().distinct() | One or more column names. | For one column: An array of values.For two or more columns: An array of arrays of values. | Used to select distinct values from the database for one or more columns. Pass in column names to get back an array of distinct values. |
var db = TAFFY([{
"item":1,
"name":"Blue Ray Player",
"price":99.99,
"type":"No"
}, {
"item":2,
name:"3D TV",
price:1799.99,
"type":"Yes"
}]);
var xyz = JSON.stringify(db().distinct("item"));
alert(xyz);<script src="https://cdnjs.cloudflare.com/ajax/libs/taffydb/2.7.2/taffy-min.js"></script>更新
你可以做这样的事情
var filter = db().filter({ price: { gt : 49 } }); // filter data
var order = filter.order('price'); // this will sort
var distinct = order.distinct('price'); // this will get distinct (at this stage TaffyDB spits out data so further chaining is not possible
var stringifiedData = JSON.stringify(distinct); // this will stringify the data
alert(stringifiedData);
var db = TAFFY(getData());
var filter = db().filter({
price: {
gt : 49
}
});
var order = filter.order('price');
var distinct = order.distinct('price');
var stringifiedData = JSON.stringify(distinct);
alert(stringifiedData);
function getData() {
return [{
"item": 1,
"name": "Gelato Topical Anesthetic",
"price": 86,
"type": false
}, {
"item": 2,
"name": "Essential Shockeye and Lip",
"price": 4,
"type": true
}, {
"item": 3,
"name": "Benazepril Hydrochloride",
"price": 32,
"type": false
}, {
"item": 4,
"name": "Simulect",
"price": 4,
"type": false
}, {
"item": 5,
"name": "Pollens - Weeds, Marshelder/Poverty Mix",
"price": 59,
"type": true
}, {
"item": 6,
"name": "Carvedilol",
"price": 88,
"type": true
}, {
"item": 7,
"name": "CardinalHealth bathing wipe with dimethicone",
"price": 100,
"type": true
}, {
"item": 8,
"name": "Phentermine Hydrochloride",
"price": 10,
"type": false
}, {
"item": 9,
"name": "NABUMETONE",
"price": 14,
"type": false
}, {
"item": 10,
"name": "Members Mark Nicotine",
"price": 82,
"type": true
}, {
"item": 11,
"name": "Amitriptyline Hydrochloride",
"price": 13,
"type": false
}, {
"item": 12,
"name": "Oxygen",
"price": 98,
"type": true
}, {
"item": 13,
"name": "buspirone hydrochloride",
"price": 72,
"type": true
}, {
"item": 14,
"name": "Antibacterial Foaming Hand Sanitizer",
"price": 94,
"type": false
}, {
"item": 15,
"name": "Nevirapine",
"price": 61,
"type": false
}, {
"item": 16,
"name": "Tamsulosin Hydrochloride",
"price": 39,
"type": true
}, {
"item": 17,
"name": "Aveeno Baby Daily Moisture",
"price": 31,
"type": false
}, {
"item": 18,
"name": "Ultra Nutrition Ampoule",
"price": 5,
"type": true
}, {
"item": 19,
"name": "Glytone essentials rejuvenate daily",
"price": 36,
"type": false
}, {
"item": 20,
"name": "all day allergy relief",
"price": 75,
"type": true
}, {
"item": 21,
"name": "CLE DE PEAU BEAUTE SILKY FOUNDATION I",
"price": 7,
"type": true
}, {
"item": 22,
"name": "GABAPENTIN",
"price": 48,
"type": false
}, {
"item": 23,
"name": "SUN Solar Defense Hydrating",
"price": 44,
"type": false
}, {
"item": 24,
"name": "Carvedilol",
"price": 38,
"type": false
}, {
"item": 25,
"name": "Metoprolol succinate",
"price": 59,
"type": false
}, {
"item": 26,
"name": "Prosacea",
"price": 38,
"type": true
}, {
"item": 27,
"name": "Russian Olive",
"price": 50,
"type": true
}, {
"item": 28,
"name": "Silver Maple",
"price": 33,
"type": true
}, {
"item": 29,
"name": "Dove Ultimate Visibly Smooth Nature Fresh",
"price": 28,
"type": true
}, {
"item": 30,
"name": "Crayola Wild Blue Yonder Roll On Hand Sanitizer",
"price": 89,
"type": true
}, {
"item": 31,
"name": "Oxygen",
"price": 70,
"type": false
}, {
"item": 32,
"name": "infants fever reducer and pain reliever",
"price": 80,
"type": false
}, {
"item": 33,
"name": "equaline childrens ibuprofen oral suspension",
"price": 17,
"type": false
}, {
"item": 34,
"name": "Head and Shoulders Dual Sachets",
"price": 80,
"type": false
}, {
"item": 35,
"name": "Kadian",
"price": 22,
"type": true
}, {
"item": 36,
"name": "Fentanyl",
"price": 90,
"type": true
}, {
"item": 37,
"name": "Vicks DayQuil and Vicks NyQuil",
"price": 14,
"type": false
}, {
"item": 38,
"name": "Dr. Scholls",
"price": 48,
"type": true
}, {
"item": 39,
"name": "Promethazine VC With Codeine",
"price": 67,
"type": false
}, {
"item": 40,
"name": "Prestige",
"price": 20,
"type": true
}, {
"item": 41,
"name": "propranolol hydrochloride",
"price": 40,
"type": false
}, {
"item": 42,
"name": "KROGER",
"price": 96,
"type": false
}, {
"item": 43,
"name": "Hydrochlorothiazide",
"price": 16,
"type": false
}, {
"item": 44,
"name": "Herpes Sores",
"price": 76,
"type": true
}, {
"item": 45,
"name": "TRICHOPHYTON MENTAGROPHYTES",
"price": 10,
"type": true
}, {
"item": 46,
"name": "Promethazine Hydrochloride",
"price": 45,
"type": true
}, {
"item": 47,
"name": "Allergy",
"price": 27,
"type": false
}, {
"item": 48,
"name": "Hydrocortisone",
"price": 69,
"type": false
}, {
"item": 49,
"name": "ChapStick Active Sport Ready",
"price": 91,
"type": false
}, {
"item": 50,
"name": "Orange Pekoe Tea",
"price": 25,
"type": false
}, {
"item": 51,
"name": "care one miconazole 7",
"price": 63,
"type": true
}, {
"item": 52,
"name": "ACER NEGUNDO POLLEN",
"price": 24,
"type": false
}, {
"item": 53,
"name": "Ceftriaxone",
"price": 50,
"type": true
}, {
"item": 54,
"name": "Smart Sense Dual Action Complete",
"price": 35,
"type": true
}, {
"item": 55,
"name": "Effexor",
"price": 2,
"type": false
}, {
"item": 56,
"name": "Clopidogrel Bisulfate",
"price": 82,
"type": false
}, {
"item": 57,
"name": "Methenamine Hippurate",
"price": 89,
"type": false
}, {
"item": 58,
"name": "Glumetza",
"price": 57,
"type": false
}, {
"item": 59,
"name": "Duloxetine",
"price": 98,
"type": true
}, {
"item": 60,
"name": "Relaxatone",
"price": 88,
"type": false
}, {
"item": 61,
"name": "Blues - Mood Support",
"price": 89,
"type": true
}, {
"item": 62,
"name": "Phenytek",
"price": 10,
"type": true
}, {
"item": 63,
"name": "LEUKERAN",
"price": 20,
"type": true
}, {
"item": 64,
"name": "Citalopram",
"price": 17,
"type": true
}, {
"item": 65,
"name": "ACTIFIRM RECOVERY EYE",
"price": 34,
"type": true
}, {
"item": 66,
"name": "Potassium Chloride",
"price": 99,
"type": false
}, {
"item": 67,
"name": "Mucus Relief",
"price": 63,
"type": false
}, {
"item": 68,
"name": "Cold and Flu BP",
"price": 52,
"type": false
}, {
"item": 69,
"name": "AQUAFRESH",
"price": 10,
"type": true
}, {
"item": 70,
"name": "Buspirone Hydrochloride",
"price": 100,
"type": false
}, {
"item": 71,
"name": "Childrens Allergy Relief",
"price": 91,
"type": false
}, {
"item": 72,
"name": "PANCRELIPASE",
"price": 96,
"type": true
}, {
"item": 73,
"name": "Hydrocodone Bitartrate and Acetaminophen",
"price": 63,
"type": false
}, {
"item": 74,
"name": "Dicyclomine Hydrochloride",
"price": 2,
"type": false
}, {
"item": 75,
"name": "clear lax",
"price": 98,
"type": false
}, {
"item": 76,
"name": "Doxycycline",
"price": 44,
"type": false
}, {
"item": 77,
"name": "NO-AD 45 Sunscreen",
"price": 99,
"type": false
}, {
"item": 78,
"name": "Oxygen",
"price": 36,
"type": false
}, {
"item": 79,
"name": "Spa Originals Antibacterial Gold Hand",
"price": 26,
"type": false
}, {
"item": 80,
"name": "Citalopram",
"price": 36,
"type": true
}, {
"item": 81,
"name": "BAMBOO SALT Eunganggo Jook Yeom Toothpaste",
"price": 81,
"type": false
}, {
"item": 82,
"name": "Cefdinir",
"price": 32,
"type": true
}, {
"item": 83,
"name": "Pravastatin Sodium",
"price": 69,
"type": true
}, {
"item": 84,
"name": "Metoclopramide",
"price": 61,
"type": false
}, {
"item": 85,
"name": "Loratadine and Pseudoephedrine",
"price": 25,
"type": true
}, {
"item": 86,
"name": "Fluoxetine",
"price": 52,
"type": false
}, {
"item": 87,
"name": "Good Sense Nicotine",
"price": 53,
"type": false
}, {
"item": 88,
"name": "triamcinolone acetonide",
"price": 78,
"type": true
}, {
"item": 89,
"name": "Warm Deep Original",
"price": 60,
"type": false
}, {
"item": 90,
"name": "Pollens - Trees, Tree Mix 11",
"price": 1,
"type": false
}, {
"item": 91,
"name": "Acidil",
"price": 69,
"type": true
}, {
"item": 92,
"name": "Rugby GAS RELIEF",
"price": 67,
"type": false
}, {
"item": 93,
"name": "Pandanus Calc. carb.",
"price": 94,
"type": false
}, {
"item": 94,
"name": "Palgic",
"price": 44,
"type": false
}, {
"item": 95,
"name": "Benzamycin Pak",
"price": 41,
"type": false
}, {
"item": 96,
"name": "Labetalol Hydrochloride",
"price": 31,
"type": true
}, {
"item": 97,
"name": "4 Way",
"price": 36,
"type": false
}, {
"item": 98,
"name": "REPAIRWEAR ANTI -AGING MAKEUP",
"price": 30,
"type": false
}, {
"item": 99,
"name": "leader cough dm",
"price": 28,
"type": true
}, {
"item": 100,
"name": "Magnesium Oxide",
"price": 82,
"type": false
}];
}<script src="https://cdnjs.cloudflare.com/ajax/libs/taffydb/2.7.2/taffy-min.js"></script>于 2015-05-28T17:01:58.720 回答