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Simple and stupid ORM for SQLite on Android

License: MIT License

Java 100.00%

sorm's Introduction

SORM

Simple and stupid ORM for Android

setup

add this project as you Android project library

Usage

Create a table

the model

@Table  
public class User extends Model {  

	@Column  
	@Index //index support
	private long userid; 

	@Column   
	private int age;  

	@Column  
	private String name;  

	public long getUserid() {
		return userid;
	}

	public void setUserid(long userid) {
		this.userid = userid;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

}

update & automantily insert if not exist

	Admin a1 = new Admin();  
	a1.setAdminName("a111");  
	a1.setId(1);  
	a1.save(getContext());  
	//or you can save in async way
	a1.saveAsync(getContext(),  new ORMcallback() {

				@Override
				public void onFinish() {
					
				}

				@Override
				public void onFaild() {
					
				}
			});

query

	List<Admin> admins = new Query(new Selector().from(Admin.class))
				.excute(getContext());  
	// or query  in async way
	Selector selector = new Selector().from(Admin.class);
	new Query(selector).excuteAsync(getContext(), new QueryCallback() {

			@Override
			public void onFinish(Object result) {
				List<Admin> res = (List<Admin>) result;
			}
		});

delete

	List<Admin> admins = new Query(new Selector().from(Admin.class))
				.excute(getContext());  
	for(Admin a: admins){  
		a.delete(getContext());  
		//or you can save in async way
		a.deleteAsync(getContext(),  new ORMcallback() {

				@Override
				public void onFinish() {
				
				}

				@Override
				public void onFaild() {
				
				}
			});
	}

Five Operation

build entity

	new Creater().from(User.class).build()

insert

  
    User u = new User();    
    u.setAge(11);     
    u.setName("aaa");     
    String sql = new Inserter().insert(u ).build();

delete

	String sql = new Deletor()
				.from(User.class)
				.where("id", "=", "1")
				.and().where("age", ">", "18")
				.build();

select

	String sql = new Selector("id","title","content") //the result columns. select all(*) when nothing here
					.from(Database.class)  //table
					.distinct() // all() or distinct()
					.where("showFlag","=", 1 + "")   //`where` expression
					.and().where("version", "!=", "0")
					.groupBy("id","title")  //more than one
					.orderBy("id") //ablt to more than one
					.limit(10)
					.offset(10)
					.build();

update

	User u = new User();
	u.setAge(11);
	u.setName("bbb");
	u.setSaveTime(12354546);
	u.setId(1);
	String sql = new Updater()
					.update(u)
					.where("id", "=", "1")
					.build();

advance

drop table & index

//drop table  
String sql = new Droper().Table().from(Animal.class).build();  
//drop index  
String sql = new Droper().Index().from(Animal.class).build();  
//invoke  sql  
DBUtils.execSQL(context,sql);

//why not do this:  
new Droper().Index().from(cls).excute(getContext());  
new Droper().Table().from(cls).excute(getContext());

sorm's People

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boy1583

sorm's Issues

delete的逻辑

一般情况下：
要删除元素，该元素一般是从数据库中取出，然后进行删除

但是用户可能曲解删除的意思（or 不小心这么写了）：
没有先取出来，而是自己构造直接删除，这样就会出错了

数据库泄露

see：

06-08 05:36:29.440: W/SQLiteConnectionPool(5400): A SQLiteConnection object for database '/data/data/io.github.jayin.test/databases/mydb.db' was leaked!  Please fix your application to end transactions in progress properly and to close the database when it is no longer needed.

06-08 05:36:29.440: W/SQLiteConnectionPool(5400): A SQLiteConnection object for database '/data/data/io.github.jayin.test/databases/mydb.db' was leaked! Please fix your application to end transactions in progress properly and to close the database when it is no longer needed.

support `* where(expression)`

support * where(expression)
it't more expanding than only where(String column, String operation, String value)

support index

小重构一下Creater.buildColumns and Inserter.insert

add new utils

提供一个添加/批量删除的接口

这个也算是基本需求 see #15

close db after querying

where语句对于条件是String 失效

Delete From User Where id = 1 and name != Jason

should be:

Delete From User Where id = 1 and name != "Jason"

more easy:

Delete From User Where id = "1" and name != "Jason"

sqlite数据库会自动帮你转

支持多层次继承

目前仅支持一层：

User extends Model

需求有可能是：

BasicEntity extends Model;

User extends BasicEntity;

Admin extends BasicEntity;

each table has only one Primary Key

bug like:

class Student extends Human {
    @PrimaryKey
    long id;

    int age;

    String name;

    List<Integer> friendid;

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<Integer> getFriendid() {
        return friendid;
    }

    public void setFriendid(List<Integer> friendid) {
        this.friendid = friendid;
    }

}

class Human extends Model {

    int height;

    int wight;

    public int getHeight() {
        return height;
    }

    public void setHeight(int height) {
        this.height = height;
    }

    public int getWight() {
        return wight;
    }

    public void setWight(int wight) {
        this.wight = wight;
    }

}

the sql below is incorrect

Create Table Student (name TEXT ,id INTEGER Primary Key AUTOINCREMENT,age INTEGER ,height INTEGER ,wight INTEGER ,__id INTEGER Primary Key AUTOINCREMENT)

typically,we are support to follow the user ---- remove the __id

查询时，若表尚未创建，改返回什么？

理论上会出现exception

返回null or 一个空的列表？

挣扎中、、

返回一个空的列表~

SQL Injection

discusses with @fritx at dade3bb

insert

Student s = new Student();
        s.setName("jayin\" or 1=\"1");
        s.save(getContext());

output

Insert Into Student (name) Values ("jayin" or 1="1")

Delete

String sql = new Deletor().from(Student.class)
                .where("name", "=", "jayin\" or 1=\"1").build();

output

Delete From Student Where name = "jayin" or 1="1"

select

String sql = new Selector().from(Student.class).where("name", "=", injection).build();

output

Select All * From Student Where name = "jayin" or 1="1"

update

String sql = new Updater().update(s).where("name", "=", injection).build();

output

Update Student Set name="jayin" or 1="1" Where name = "jayin" or 1="1"

should be:

Delete From Student Where name = "jayin\" or 1=\"1" 

Select All * From Student Where name = "jayin\" or 1=\"1"  

Update Student Set name="jayin" or 1="1" Where name = "jayin\" or 1=\"1"

SQLite有个特点，就是删除了数据，文件容量不会减少，要自行操作减少

参考：http://www.sqlite.org/lang_vacuum.html

    /**
     * 压缩数据库
     * 如果删除了大量数据，而又想缩小数据库文件占用的空间，执行 VACUUM 命令。 VACUUM      
     * 将会从头重新组织数据库。这将会使用数据库有一个空的“自由链表”， 数据库文件也会最小。但要注意的是， VACUUM      
     * 的执行会需要一些时间 （在SQLite开发时，在Linux上，大约每M字节需要半秒种），并且，      
     * 执行过程中需要原数据库文件至多两倍的临时磁盘空间。 
     * @throws DbException 抛出异常
     */
    public void CompressDb() throws DbException {
        execNonQuery("VACUUM");
    }

提供一个添加/批量删除的接口（异步）

see： #16 #15

Model.save

设计思路：
每个实体类都是一个Model(e.g. User extends Model)
如果在保存or更新一条记录的时候，显然这样做的最人性化的：

user.save()

但是弊端就是要连接数据，的给个上下文才能获得db object.那么解决办法有3种
1

user.init(context).save()

//这样虽然可以接受，但是每次插入的时候添加init(context),感觉有些少冗余？容易忘了init？

在Application里面：

DB.init(context)

那么在可以

user.save()
//在save函数里面通过静态方法的db object.获取即可

//这种也是不失为一种好解决办法，一次初始化，到处爽！但是如果换了别人来维护，很可能忘记在application里面初始化，或者从内存的角度来看，整个application均持有db object，这样浪费内存。

3
这是一种折中的办法

user.save(context)

没有一次初始化到处使用，也没有init(context) 那么冗余的感觉

这里我尝试采用第三种方法去实现。

save()的实现要点

1 同内建一个__id,来表示每一条记录
2 save()可以是插入or更新，这就是通过__id的存在性来判断了

new Query(selector).excute(context)
//expression = new selector().from()........build()

return List

jayin / sorm Goto Github PK

sorm's Introduction

SORM

setup

Usage

Create a table

update & automantily insert if not exist

query

delete

Five Operation

advance

sorm's People

Contributors

Stargazers

Watchers

Forkers

sorm's Issues

should be:

save()的实现要点

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