如何将json文件导入indexeddb? [英] How to import json file into indexeddb?
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问题描述
我正在做一个将一些数据存储在IndexedDB中的应用程序,但是我想先加载json文件中的一些数据.
I am doing an app that store some data in the IndexedDB, but I want to load first some data that is in my json file.
这是我的json文件:
Here is my json file:
{
"ciudades":[
{
"ciudad":"Asuncion",
"latitud":-25.2985296,
"longitud":-57.6710677
},
{
"ciudad":"Caaguazu",
"latitud":-25.465034,
"longitud":-56.0183859
},
{
"ciudad":"Ciudad del Este",
"latitud":-25.4933441,
"longitud":-54.6710438
},
{
"ciudad":"San Pedro",
"latitud":-24.1586759,
"longitud":-56.636503
},
{
"ciudad":"Pedro Juan Caballero",
"latitud":-22.5450875,
"longitud":-55.7618963
}
]
}
推荐答案
您按照步骤
步骤1 阅读mozilla网站
第2步创建indexedDB
step 2 create indexedDB
var ciudades = [
{
"ciudad":"Asuncion",
"latitud":-25.2985296,
"longitud":-57.6710677
},
{
"ciudad":"Caaguazu",
"latitud":-25.465034,
"longitud":-56.0183859
},
{
"ciudad":"Ciudad del Este",
"latitud":-25.4933441,
"longitud":-54.6710438
},
{
"ciudad":"San Pedro",
"latitud":-24.1586759,
"longitud":-56.636503
},
{
"ciudad":"Pedro Juan Caballero",
"latitud":-22.5450875,
"longitud":-55.7618963
}
];
var IDBSetting = {
name: "indexedDBName",
version: 1,
tables: [{
tableName: "ciudades",
keyPath: "seq",
autoIncrement: true,
index: ["ciudad", "latitud", "longitud],
unique: [false, false, false]
}]
};
! function() {
console.log("indexeDB init");
var req = indexedDB.open(IDBSetting.name, IDBSetting.version);
req.onsuccess = function(event) {
console.log("indexedDB open success");
};
req.onerror = function(event) {
console.log("indexed DB open fail");
};
//callback run init or versionUp
req.onupgradeneeded = function(event) {
console.log("init onupgradeneeded indexedDB ");
var db = event.target.result;
for (var i in IDBSetting.tables) {
var OS = db.createObjectStore(IDBSetting.tables[i].tableName, {
keyPath: IDBSetting.tables[i].keyPath,
autoIncrement: IDBSetting.tables[i].autoIncrement
});
for (var j in IDBSetting.tables[i].index) {
OS.createIndex(IDBSetting.tables[i].index[j], IDBSetting.tables[i].index[j], {
unique: IDBSetting.tables[i].unique[j]
});
}
}
}
}();
第3步addData
step 3 addData
var IDBFuncSet = {
//write
addData: function(table, data) {
var req = indexedDB.open(IDBSetting.name, IDBSetting.version);
req.onsuccess = function(event) {
try {
console.log("addData indexedDB open success");
var db = req.result;
var transaction = db.transaction([table], "readwrite");
var objectStore = transaction.objectStore(table);
var objectStoreRequest = objectStore.add(data);
} catch (e) {
console.log("addDataFunction table or data null error");
console.log(e);
}
objectStoreRequest.onsuccess = function(event) {
//console.log("Call data Insert success");
}
objectStoreRequest.onerror = function(event) {
console.log("addData error");
}
};
req.onerror = function(event) {
console.log("addData indexed DB open fail");
};
}
}
for(var i in ciudades){
IDBFuncSet.addData("ciudades",ciudades[i]);
}
第4步getData
step 4 getData
IDBFuncSet.getAllData = function(arr, table) {
try {
var req = indexedDB.open(IDBSetting.name, IDBSetting.version);
req.onsuccess = function(event) {
var db = req.result;
var transaction = db.transaction([table], "readonly");
var objectStore = transaction.objectStore(table);
var objectStoreRequest = objectStore.openCursor();
objectStoreRequest.onsuccess = function(event) {
var cursor = event.target.result;
if (cursor) {
arr.push(cursor.value);
cursor.continue();
} else {
}
}
};
req.onerror = function(event) {
console.log("getAllData indexed DB open fail");
};
} catch (e) {
console.log(e);
}
}
var ciudadesArr = [];
IDBFuncSet.getAllData(ciudadesArr, "ciudades");
console.log(ciudadesArr);
我希望这对您有帮助
这篇关于如何将json文件导入indexeddb?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
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