ReactNative 进阶（十一）：realm 数据库

npm i -S realmreact-native link

import Realm from 'realm';
/**表定义区**/export const HistoryTableName = 'History';export const CityTableName = 'City';
const HistorySchema = {    name: HistoryTableName,    primaryKey: 'id',    properties: {        id: 'int',        name: 'string',    }};
const CitySchema = {    name: CityTableName,    primaryKey: 'city_id',    properties: {        city_id: 'int',        city_name: 'string',    }};
const instance = new Realm({    schema: [        HistorySchema,        CitySchema,    ],    deleteRealmIfMigrationNeeded: true,    inMemory: false,});

/**表使用区**/export function writeToRealm(obj,tabName) {    return new Promise((resolve, reject) => {        instance.write(() => {            instance.create(tabName, obj, true)            resolve(true)        })    })}
export function queryAllFromRealm(tabName) {    return new Promise((resolve, reject) => {        let obj = instance.objects(tabName);        let objStr = JSON.stringify(obj);        resolve(JSON.parse(objStr))    })}
export function clearAllFromRealm(tabName) {    return new Promise((resolve, reject) => {        instance.write(() => {            let arrays = instance.objects(tabName);            instance.delete(arrays);            resolve(true)        })    })}
export function clearRowFromRealm(id,tabName) {    return new Promise((resolve, reject) => {        instance.write(() => {            let arrays = instance.objects(tabName);            let row = arrays.filtered('id==' + id);            instance.delete(row);            resolve(true)        })    })}

import React, {Component} from "react";import {StyleSheet, Text, ToastAndroid, TouchableHighlight, View,} from 'react-native';import {    HistoryTableName,    CityTableName,    clearAllFromRealm,    queryAllFromRealm,    writeToRealm,    clearRowFromRealm} from "./RealmUtil";
export default class TestRealm extends Component {    componentWillMount() {    }
    //表1操作    _addData() {        clearAllFromRealm(HistoryTableName);
        let row1 = {"id": 1, "name": "战狼1"};        writeToRealm(row1, HistoryTableName).then(() => {            ToastAndroid.show('写入完成1', ToastAndroid.SHORT);        });        let row2 = {"id": 2, "name": "战狼2"};        writeToRealm(row2, HistoryTableName).then(() => {            ToastAndroid.show('写入完成2', ToastAndroid.SHORT);        });    }
    _readAllData() {        queryAllFromRealm(HistoryTableName).then((list) => {            for (let key in list) {                ToastAndroid.show('id:' + list[key].id + ',name:' + list[key].name, ToastAndroid.SHORT);            }        });    }
    _updateData() {        let row2 = {"id": 2, "name": "北京222"};        writeToRealm(row2, HistoryTableName).then(() => {            ToastAndroid.show('修改完成', ToastAndroid.SHORT);        });    }
    _delRowData() {        //删除第一行        clearRowFromRealm(1, HistoryTableName).then(() => {            ToastAndroid.show('删除完成', ToastAndroid.SHORT);        });    }
    //表2操作    _addData2() {        clearAllFromRealm(CityTableName);
        let row1 = {"city_id": 1, "city_name": "上海"};        writeToRealm(row1, CityTableName).then(() => {            ToastAndroid.show('2写入完成1', ToastAndroid.SHORT);        });        let row2 = {"city_id": 2, "city_name": "北京"};        writeToRealm(row2, CityTableName).then(() => {            ToastAndroid.show('2写入完成2', ToastAndroid.SHORT);        });    }
    _readAllData2() {        queryAllFromRealm(CityTableName).then((list) => {            for (let key in list) {                ToastAndroid.show('城市ID:' + list[key].city_id + ',城市名:' + list[key].city_name, ToastAndroid.SHORT);            }        });    }
    render() {        return (            <View style={{flex: 1}}>                <View style={{padding: 10}}><Text>表1操作</Text></View>                <TouchableHighlight onPress={() => this._delRowData()} style={styles.button} underlayColor="#a5a5a5">                    <Text>删除第一行</Text>                </TouchableHighlight>                <TouchableHighlight onPress={() => this._addData()} style={styles.button} underlayColor="#a5a5a5">                    <Text>增加数据</Text>                </TouchableHighlight>                <TouchableHighlight onPress={() => this._updateData()} style={styles.button} underlayColor="#a5a5a5">                    <Text>修改数据</Text>                </TouchableHighlight>                <TouchableHighlight onPress={() => this._readAllData()} style={styles.button} underlayColor="#a5a5a5">                    <Text>读取全部数据</Text>                </TouchableHighlight>
                <View style={{padding: 10, marginTop: 10}}><Text>表2操作</Text></View>                <TouchableHighlight onPress={() => this._addData2()} style={styles.button} underlayColor="#a5a5a5">                    <Text>增加数据</Text>                </TouchableHighlight>                <TouchableHighlight onPress={() => this._readAllData2()} style={styles.button} underlayColor="#a5a5a5">                    <Text>读取全部数据</Text>                </TouchableHighlight>            </View>        );
    }}
const styles = StyleSheet.create({    button: {        margin: 3,        backgroundColor: 'white',        padding: 10,        borderBottomWidth: StyleSheet.hairlineWidth,        borderBottomColor: '#cdcdcd'    },});

adb remount

adb ls /data/data/com.testdemo/files

adb pull /data/data/com.testdemo/files/default.realm  d:/m