对Android sqlite数据库的简单熟悉

悠悠 2022-08-06 11:16 208阅读 0赞

先创建一个接口，源码如下：

package service;
    
    import java.util.List;
    import java.util.Map;
    //声明一个接口，好让personDao来实现
    public interface PersonService {
    	public boolean addPerson(Object[] params);
    	
    	public boolean deletePerson(Object[] params);
    	
    	public boolean updataPerson(Object[] params);
    	
    	public Map<String,String> viewPerson(String[] selectionArgs);
    	
    	public List<Map<String,String>> listPersonMaps(String[] selectionArgs);
    }

再创建一个Dao，源码如下：

package dao;
    
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    import android.content.Context;
    import android.database.Cursor;
    import android.database.sqlite.SQLiteDatabase;
    
    import com.sunmoon.notification.db.DbOpenHelper;
    
    import service.PersonService;
    
    public class personDao implements PersonService {
    
    	private DbOpenHelper helper = null;
    
    	public personDao(Context context) {
    		helper = new DbOpenHelper(context);
    	}
    
    	//插入数据
    	@Override
    	public boolean addPerson(Object[] params) {
    		boolean flag = false;
    		SQLiteDatabase database = null;
    		try {
    			String sql = "insert into person(name,address,sex) values(?,?,?)";
    			database = helper.getWritableDatabase();
    			database.execSQL(sql, params);
    			flag = true;
    
    		} catch (Exception e) {
    
    		} finally {
    			if (database != null) {
    				database.close();
    			}
    		}
    
    		return flag;
    	}
    
    	
    	//删除数据
    	@Override
    	public boolean deletePerson(Object[] params) {
    		boolean flag = false;
    		SQLiteDatabase database = null;
    
    		try {
    			String sql = "delete from person where id = ?";
    			database = helper.getWritableDatabase();
    			database.execSQL(sql, params);
    
    			flag = true;
    
    		} catch (Exception e) {
    		} finally {
    			if (database != null) {
    				database.close();
    			}
    		}
    		return false;
    	}
    
    	//更新数据
    	@Override
    	public boolean updataPerson(Object[] params) {
    		boolean flag = false;
    		SQLiteDatabase database = null;
    		try {
    			String sql = "update person set name = ?,address = ?, sex = ? where id = ? ";
    			database = helper.getWritableDatabase();
    			database.execSQL(sql, params);
    		} catch (Exception e) {
    		} finally {
    			if (database != null) {
    				database.close();
    			}
    		}
    		return flag;
    	}
    
    	//查询单个数据
    	@Override
    	public Map<String, String> viewPerson(String[] selectionArgs) {
    		Map<String, String> map = new HashMap<String, String>();
    		SQLiteDatabase database = null;
    		try {
    			String sql = "select * from person where id = ?";
    			database = helper.getWritableDatabase();
    			Cursor cursor = database.rawQuery(sql, selectionArgs);
    
    			int colums = cursor.getColumnCount();
    			while (cursor.moveToNext()) {
    				for (int i = 0; i < colums; i++) {
    					String cols_name = cursor.getColumnName(i);
    					String cols_value = cursor.getString(cursor
    							.getColumnIndex(cols_name));
    					if (cols_value == null) {
    						cols_value = "";
    					}
    					map.put(cols_name, cols_value);
    
    				}
    			}
    
    		} catch (Exception e) {
    		} finally {
    			if (database != null) {
    				database.close();
    			}
    		}
    
    		return map;
    	}
    
    	//查询多个数据
    	@Override
    	public List<Map<String, String>> listPersonMaps(String[] selectionArgs) {
    		List<Map<String, String>> list = new ArrayList<Map<String, String>>();
    		String sql = "select * from person";
    		SQLiteDatabase database = null;
    		try {
    			database = helper.getReadableDatabase();
    			Cursor cursor = database.rawQuery(sql, selectionArgs);
    			int colums = cursor.getColumnCount();
    			while (cursor.moveToNext()) {
    				Map<String, String> map = new HashMap<String, String>();
    				for (int i = 0; i < colums; i++) {
    					String cols_name = cursor.getColumnName(i);
    					String cols_value = cursor.getString(cursor
    							.getColumnIndex(cols_name));
    					if (cols_value == null) {
    						cols_value = "";
    					}
    					map.put(cols_name, cols_value);
    				}
    				list.add(map);
    			}
    
    		} catch (Exception e) {
    		} finally {
    			if (database != null) {
    				database.close();
    			}
    		}
    		return list;
    	}
    
    }

在一个测试类中测试,源码如下:

package com.sunmoon.notification.test;
    
    import java.util.List;
    import java.util.Map;
    
    import service.PersonService;
    
    import com.sunmoon.notification.db.DbOpenHelper;
    
    import dao.personDao;
    
    import android.test.AndroidTestCase;
    import android.util.Log;
    
    public class myTest extends AndroidTestCase {
    
    	public myTest() {
    	}
    	
    	public void createDb(){
    		DbOpenHelper helper = new DbOpenHelper(getContext());
    		helper.getWritableDatabase();
    	}
    	
    	public void insertDB(){
    		PersonService service = new personDao(getContext());
    		Object[] params = {"李四","四川","女"};
    		boolean flag = service.addPerson(params);
    		System.out.println("-->"+flag);
    	}
    	public void delteDB(){
    		PersonService service = new personDao(getContext());
    		Object[] params = {1};
    		boolean flag = service.deletePerson(params);
    		System.out.println("-->"+flag);
    	}
    	
    	public void updateDB(){
    		PersonService service = new personDao(getContext());
    		Object[] params = {"王五","内江","不详","3"};
    		service.updataPerson(params);
    	}
    	
    	public void viewDB(){
    		PersonService service = new personDao(getContext());
    		String[] serlectionArgs = {"3"};
    		Map<String,String> map = service.viewPerson(serlectionArgs);
    		Log.i("Test","-->>"+map.toString());
    		
    	}
    	
    	public void listDB(){
    		PersonService service = new personDao(getContext());
    		List<Map<String,String>> list =  service.listPersonMaps(null);
    		Log.i("Test","-->>"+list.toString());
    		
    	}
    	
    	
    	
    	
    	
    	
    	
    	
    	
    }

在测试的类之前，要在清单文件中进行配置

还得要在   application中加入一个uses-library  例如：