expo-sqlite-wrapper

expo-sqlite-wrapper

This is an ORM, build around expo-sqlite. It will make operation like UPDATE,SELECT AND INSERT a lot easier to handle

Installations

 npm install expo-sqlite expo-sqlite-wrapper

Installation for expo-sqlite read https://docs.expo.dev/versions/latest/sdk/sqlite/

Usage

SetupModules

"show source" // this is only specific for hermes installations, read below to understand more about this.
import  { IBaseModule, TableStructor, ColumnType, IQueryResultItem } from 'expo-sqlite-wrapper'
export type TableNames = "Parents" | "Childrens";

export class Parent extends IBaseModule<TableNames>{
 name: string;
 email: string;
 // Using IQueryResultItem is optional, you could simple use Child[]
 children: IQueryResultItem<Child,TableNames>[];
 constructor(name:string, email: string ){
   super("Parents");
   this.name = name;
   this.email = email;
   this.children = [];
 }
 
  static GetTableStructor() {
    return new TableStructor<Parent, TableNames>(
      "Parents",
      [
        { columnName: x=> x.id, columnType: ColumnType.Number, nullable: false, isPrimary: true, autoIncrement: true },
        { columnName: x=> x.name, columnType: ColumnType.String },
        //isUnique acts as an Id too as the library will chack if there exist an item with the same field value and will update instead.
         { columnName: x=> x.email, columnType: ColumnType.String, isUnique: true } 
      ]
    )
  }
}


export class Child extends IBaseModule<TableNames>{
 someField: string;
 parentId?: number;
 constructor(someField:string, parentId?: number ){
   super("Childrens");
   this.someField = someField;
   this.parentId = parentId;
 }
  
  static GetTableStructor() {
    return new TableStructor<Child, TableNames>(
      "Childrens",
      [
        { columnName: x=> x.id, columnType: ColumnType.Number, nullable: false, isPrimary: true, autoIncrement: true },
        { columnName: x=> x.someField, columnType: ColumnType.String },
        { columnName: x=> x.parentId, columnType: ColumnType.Number, nullable: true },
      ],
       [
        { contraintTableName: "Parents", contraintColumnName: "id", columnName: x=> x.parentId }
      ], 
      // You could always handle how the item gets created when its returned from the database.
      // The database return a json item, if you want to convert it to class then use this(onItemCreate) to generate the class
      (item: T)=> {
           var child= new Child(item.someField, item.parentId);
           child.id= item.id;
           return child;
      } 
    )
  }
}

Setup dbContexts

import createDbContext, { IDatabase, IQueryResultItem, IBaseModule } from 'expo-sqlite-wrapper'
import * as SQLite from 'expo-sqlite';
const tables = [Parent.GetTableStructor(), Child.GetTableStructor()]
export default class DbContext {
  databaseName: string = "mydatabase.db";
  database: IDatabase<TableNames>;
  constructor() {
    this.database = createDbContext<TableNames>(tables, async () => SQLite.openDatabase(this.databaseName));
  }
}

Using the dbContexts

const dbContext = new DbContext();
const App=()=> {

React.useEffect(()=> {
  // When the app start 
  const firstRun= async()=> {
  // this will create the database tables if it not already created
  await dbContext.database.setUpDataBase();
  
  }
  firstRun();
},[]);

const addItem= async ()=> {
  var item = await dbContext.database.save(new Parent("testName", "[e-mail]"));
  var child = await dbContext.database.save(new Child("testName",item.id));
  // There is many different way to select
  // the basic way 
  // this will be converted to [SELECT * FROM PARENTS WHERE name = ?] WHERE ? is the arguments
   var item = await dbContext.database.where<Parent>("Parents", { name: "testName"})
  // and there is a much uniqe way, for IQuery read below to see what you methods it containe
   var item = await dbContext.database.query<Parent>("Parents")
   .Column(x=> x.name)
   .EqualTo("testName")
   .firstOrDefault();
   item.name= "test"
   item.saveChanges();
 
   // You could also load the children when using query
   // this will be converted to [Select * from Parents where (name in (?,?)) OR (email like %?%)] WHERE ? is the arguments.
   // Also make note that if arguments in IN() is empty or undefined the select Sats will remove the select for the column Name
   // and the select will be [Select * from Parents where (email like %?%)] the same for EqualTo etc..
   
    var item = await dbContext.database.query<Parent>("Parents")
     .Start().Column(x=> x.name).IN(["name", "testName"]).End()
     .OR()
     .Start().Column(x=> x.email).Contains("test@").End()
     .LoadChildren("Childrens", x=> x.id)
     .With<Child>(x=> x.parentId)
     .AssignTo(x=> x.children).toList();
     
     
     // You could also use simple sql 
    var item=  (await dbContext.database.find("Select * from Parents where (name in (?,?)) OR (email like %?%)", ["name", "testName","test@" ])) as Parent[];
    
    // you could also watch the db operation very easy.
    useEffect(()=> {
     var watcher = dbContext.database.watch<Parent>("Parents");
     watcher.onSave = async (item, operation)=> {
       // operation = "INSERT" OR "UPDATE"
        console.log(item);
     }
     
     watcher.onDelete = async (item)=> {
        console.log(item);
     }
     
     return ()=> watcher.removeWatch();
    },[])
    
}
}

IQuery

interface IQuery<T, D extends string> {
    Column: <B>(item: ((x: T) => B)|string) => IQuery<T, D>;
    EqualTo: (value: SingleValue) => IQuery<T, D>;
    Contains:  (value: StringValue) => IQuery<T, D>;
    StartWith:  (value: StringValue) => IQuery<T, D>;
    EndWith:  (value: StringValue) => IQuery<T, D>;
    NotEqualTo: (value: SingleValue) => IQuery<T, D>;
    EqualAndGreaterThen: <B>(value: NumberValue) => IQuery<T, D>;
    EqualAndLessThen: (value: NumberValue) => IQuery<T, D>;
    Start: () => IQuery<T, D>;
    End: () => IQuery<T, D>;
    OR: () => IQuery<T, D>;
    AND: () => IQuery<T, D>;
    GreaterThan: (value: NumberValue) => IQuery<T, D>;
    LessThan: (value: ((x: T) => B) | NumberValue) => IQuery<T, D>;
    IN: (value: ArrayValue) => IQuery<T, D>;
    NotIn: (value: ArrayValue) => IQuery<T, D>;
    Null: () => IQuery<T, D>;
    NotNull: () => IQuery<T, D>;
    OrderByDesc: <B>(item: ((x: T) => B) | string) => IQuery<T, D>;
    OrderByAsc: <B>(item: ((x: T) => B) | string) => IQuery<T, D>;
    Limit: (value: number) => IQuery<T, D>;

    // Load array
    LoadChildren: <B>(childTableName: D, parentProperty: ((x: T) => B)|string) => IChildQueryLoader<B, T, D>;
    // load object
    LoadChild: <B>(childTableName: D, parentProperty: ((x: T) => B)|string) => IChildQueryLoader<B, T, D>
    // Delete based on Query, this will create Delete from 
    delete: ()=> Promise<void>;
    // get the first item or undefined
    firstOrDefault: () => Promise<IQueryResultItem<T, D> | undefined>;
    // Try to find the Queried item if not found then insert item and return it from the database.
    findOrSave: (item: IBaseModule<D>) => Promise<IQueryResultItem<T, D>>;
    // return a list
    toList: () => Promise<IQueryResultItem<T, D>[]>;
    getQueryResult: () => IQuaryResult<D>;
}

IDatabase

export interface IDatabase<D extends string> {
    isClosed?: boolean,
    // Its importend that,createDbContext return new data database after this is triggered
    tryToClose: (name: string) => Promise<boolean>,
    // save and delete method begintransaction if beginTransaction not executed and there is more then one item
    beginTransaction:()=> Promise<void>;
    commitTransaction:()=> Promise<void>;
    rollbackTransaction:()=> Promise<void>;

    // Auto close the db after every ms.
    // The db will be able to refresh only if there is no db operation is ongoing.
    // This is useful, so that it will use less memory as SQlite tends to store transaction in memories which causes the increase in memory over time.
    // its best to use ms:3600000
    // the db has to be ideal for ms to be able to close it.
    startRefresher: (ms: number, dbName: string) => void;
    // the columns for the current table
    allowedKeys: (tableName: D) => Promise<string[]>;
    // convert object to IQueryResultItem
    asQueryable: <T>(item: IBaseModule<D>, tableName?: D) => Promise<IQueryResultItem<T, D>>
    // add a watcher for the selected table, this is a global watch. 
    // no matter which dbContext you use it will trigger when a change to the database item for the selected table is chaged
    watch: <T>(tableName: D) => IWatcher<T, D>;
    // start a Query
    query: <T>(tableName: D) => IQuery<T, D>;
    find: (query: string, args?: any[], tableName?: D) => Promise<IBaseModule<D>[]>
    // insert or update depends on Id or isUnique columns
    save: <T>(item?: IBaseModule<D> | (IBaseModule<D>[]), insertOnly?: Boolean, tableName?: D) => Promise<T[]>;
    where: <T>(tableName: D, query?: any | T) => Promise<T[]>;
    // delete an item, there is no check for contraint values, so make sure you do that befor you delete the item
    delete: (item: IBaseModule<D> | (IBaseModule<D>[]), tableName?: D) => Promise<void>;
    // execute a query
    execute: (query: string, args?: any[]) => Promise<boolean>;
    // drop all tables in the database
    dropTables: () => Promise<void>;
    // Check and create table if not exist. this only run once when the app start else set forceCheck= true to check again
    setUpDataBase: (forceCheck?: boolean) => Promise<void>;
    // check if the modules differ from the database table.
    // You will have to apply those changes your selef. You could make an ApplyChanges and get the values then drops all tables and 
    // recreated it using setUpDataBase(true) then insert it them again. 
    tableHasChanges: (item: TablaStructor<D>) => Promise<boolean>;
}

obfuscator-io-metro-plugin

If you use obfuscator-io-metro-plugin and use IQuery expression eg Column(x=> x.name) then you should have those settings below. as the obfuscator will rewite all properties and the library can not read those.

const jsoMetroPlugin = require("obfuscator-io-metro-plugin")(
  {
    compact: false,
    sourceMap: true,
    controlFlowFlattening: true,
    controlFlowFlatteningThreshold: 0, // Very Importend
    numbersToExpressions: true,
    simplify: true,
    shuffleStringArray: true,
    splitStrings: true,
    stringArrayThreshold: 0 // Very Importend
  },
  {
    runInDev: false /* optional */,
    logObfuscatedFiles: true /* optional generated files will be located at ./.jso */,
    sourceMapLocation:
      "./index.android.bundle.map" /* optional  only works if sourceMap: true in obfuscation option */,
  }
);

Hermes

If you are using hermes and using expression ex x=> x.id then you will have too add show source on top of the files where you are using it. Its best to gather all the queries in a one class and add show source on top of this specific class, eg repository and the db classes on the example above.

Otherwise if you still want to use more advanced obfuscator settings then you should use Column("name") instead of expression x=> x.name as the library could still read the string and count it as a column.

This Library is new and I am using it for my project and decided too put it on npm, so there may be some issues discovered later. Please report those so I could make sure to fix them.