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1.0版代码:
package com.swust.sqlitedatabase.test; import com.swust.sqlitedatabase.myOpenHelper; import android.database.sqlite.SQLiteDatabase; import android.test.AndroidTestCase; public class TestCase extends AndroidTestCase { public void test(){ //第一个参数：this->现在应用没启动，没有，真正的时候用this。所以获取虚拟上下文getContext() //第二个参数：数据库文件 //第四个参数：版本号 //recNO字段是系统的，无视 myOpenHelper moh = new myOpenHelper(getContext(), "people.db", null, 1); //如果数据库不存在，先创建数据库，再获取可读可写数据库对象，如果数据存在，就直接打开 SQLiteDatabase db=moh.getWritableDatabase(); //创建对象也可读可写,如果存储空间满了，那么返回只读数据库对象 //SQLiteDatabase db=moh.getReadableDatabase(); } public void insert(){ myOpenHelper moh = new myOpenHelper(getContext(), "people.db", null, 1); SQLiteDatabase db=moh.getWritableDatabase(); //数据库char ,double等都是字符串，因为这个轻量级数据不检测数据 db.execSQL("insert into person(name,salary,phone)values(?,?,?)",new Object[]{"王**","25.34",12.345}); db.execSQL("insert into person(name,salary,phone)values(?,?,?)",new Object[]{"王**大学",25.34,"12.345"}); db.execSQL("insert into person(name,salary,phone)values(?,?,?)",new Object[]{"王**","25.34",12.345}); db.execSQL("insert into person(name,salary,phone)values(?,?,?)",new Object[]{"王**大学",25.34,"12.345"}); db.close(); } }
插入后：
删除：
public void delete(){ myOpenHelper moh = new myOpenHelper(getContext(), "people.db", null, 1); SQLiteDatabase db=moh.getWritableDatabase(); db.execSQL("delete from person where name =?",new Object[]{"王**"}); }
之后，字段名字为“王**”的被删除
效果：
-------------------------------------
代码未优化：
package com.swust.sqlitedatabase.test; import com.swust.sqlitedatabase.myOpenHelper; import android.database.sqlite.SQLiteDatabase; import android.test.AndroidTestCase; public class TestCase extends AndroidTestCase { public void test(){ //第一个参数：this->现在应用没启动，没有，真正的时候用this。所以获取虚拟上下文getContext() //第二个参数：数据库文件 //第四个参数：版本号 //recNO字段是系统的，无视 myOpenHelper moh = new myOpenHelper(getContext(), "people.db", null, 1); //如果数据库不存在，先创建数据库，再获取可读可写数据库对象，如果数据存在，就直接打开 SQLiteDatabase db=moh.getWritableDatabase(); //创建对象也可读可写,如果存储空间满了，那么返回只读数据库对象 //SQLiteDatabase db=moh.getReadableDatabase(); } public void insert(){ myOpenHelper moh = new myOpenHelper(getContext(), "people.db", null, 1); SQLiteDatabase db=moh.getWritableDatabase(); //数据库char ,double等都是字符串，因为这个轻量级数据不检测数据 db.execSQL("insert into person(name,salary,phone)values(?,?,?)",new Object[]{"王**","25.34",12.345}); db.execSQL("insert into person(name,salary,phone)values(?,?,?)",new Object[]{"王**大学",25.34,"12.345"}); db.execSQL("insert into person(name,salary,phone)values(?,?,?)",new Object[]{"王**","25.34",12.345}); db.execSQL("insert into person(name,salary,phone)values(?,?,?)",new Object[]{"王树青大学",25.34,"12.345"}); db.close(); } public void delete(){ myOpenHelper moh = new myOpenHelper(getContext(), "people.db", null, 1); SQLiteDatabase db=moh.getWritableDatabase(); db.execSQL("delete from person where name =?",new Object[]{"王**"}); } }
优化后：
package com.itheima.sqlitedatabase.test; import com.itheima.sqlitedatabase.MyOpenHelper; import android.content.ContentValues; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.test.AndroidTestCase; public class TestCase extends AndroidTestCase { //此时测试框架还没有初始化完毕，没有虚拟上下文对象 // private MyOpenHelper oh = new MyOpenHelper(getContext(), "people.db", null, 1); private MyOpenHelper oh; private SQLiteDatabase db; public void test(){ //getContext():获取一个虚拟的上下文 MyOpenHelper oh = new MyOpenHelper(getContext(), "people.db", null, 1); //如果数据库不存在，先创建数据库，再获取可读可写的数据库对象，如果数据库存在，就直接打开 SQLiteDatabase db = oh.getWritableDatabase(); //如果存储空间满了，那么返回只读数据库对象 // SQLiteDatabase db = oh.getReadableDatabase(); } //测试框架初始化完毕之后，在测试方法执行之前，此方法调用 @Override protected void setUp() throws Exception { super.setUp(); oh = new MyOpenHelper(getContext(), "people.db", null, 1); db = oh.getWritableDatabase(); } //测试方法执行完毕之后，此方法调用 @Override protected void tearDown() throws Exception { // TODO Auto-generated method stub super.tearDown(); db.close(); } public void insert(){ // db.execSQL("insert into person (name, salary, phone)values(?, ?, ?)", new Object[]{"小志的老婆[1]", "13000", 138438}); // db.execSQL("insert into person (name, salary, phone)values(?, ?, ?)", new Object[]{"小志的儿子", 14000, "13888"}); db.execSQL("insert into person (name, salary, phone)values(?, ?, ?)", new Object[]{"小志", 14000, "13888"}); } public void delete(){ db.execSQL("delete from person where name = ?", new Object[]{"小志"}); } public void update(){ db.execSQL("update person set phone = ? where name = ?", new Object[]{186666, "小志的儿子"}); } public void select(){ Cursor cursor = db.rawQuery("select name, salary from person", null); while(cursor.moveToNext()){ //通过列索引获取列的值 String name = cursor.getString(cursor.getColumnIndex("name")); String salary = cursor.getString(1); System.out.println(name + ";" + salary); } } public void insertApi(){ //把要插入的数据全部封装至ContentValues对象 ContentValues values = new ContentValues(); values.put("name", "游天龙"); values.put("phone", "15999"); values.put("salary", 16000); db.insert("person", null, values); } public void deleteApi(){ int i = db.delete("person", "name = ? and _id = ?", new String[]{"小志的儿子", "3"}); System.out.println(i); } public void updateApi(){ ContentValues values = new ContentValues(); values.put("salary", 26000); int i = db.update("person", values, "name = ?", new String[]{"游天龙"}); System.out.println(i); } public void selectApi(){ Cursor cursor = db.query("person", null, null, null, null, null, null, null); while(cursor.moveToNext()){ String name = cursor.getString(cursor.getColumnIndex("name")); String phone = cursor.getString(cursor.getColumnIndex("phone")); String salary = cursor.getString(cursor.getColumnIndex("salary")); System.out.println(name + ";" + phone + ";" + salary); } } public void transaction(){ try{ //开启事务 db.beginTransaction(); ContentValues values = new ContentValues(); values.put("salary", 12000); db.update("person", values, "name = ?", new String[]{"小志"}); values.clear(); values.put("salary", 16000); db.update("person", values, "name = ?", new String[]{"小志的儿子"}); int i = 3/0; //设置 事务执行成功 db.setTransactionSuccessful(); } finally{ //关闭事务，同时提交，如果已经设置事务执行成功，那么sql语句就生效了，反之，sql语句回滚 db.endTransaction(); } } }
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原文地址：http://www.cnblogs.com/shuqingstudy/p/4890626.html
