SQLite增删改查（自己写SQL语句）

在/article/6636587.html中，实现了数据库的创建和升级。没有增加向数据库中添加、删除、修改和查询Data的代码，这里用一种方式实现这些功能。

一、在先前的工程中增加PersonService接口和PersonDao类。看下图：

package com.bruce.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 android.util.Log;

import com.bruce.db_test.db.DbOpenHelper;
import com.bruce.db_test.service.PersonService;

public class PersonDao implements PersonService {
private String TAG = "MyTest";
private DbOpenHelper helper = null;
public PersonDao(Context context){
helper = new DbOpenHelper(context);
}
@Override
public boolean insertPerson(Object[] values) {
Log.i(TAG, "-->insertPerson");
boolean flag = false;
SQLiteDatabase database = null;
try {
String sql = "insert into person(name,address,sex) values(?,?,?)";
database = helper.getWritableDatabase();
database.execSQL(sql, values);
flag = true;
Log.i(TAG, "-->insertPerson"+ flag);
} catch (Exception e) {
e.printStackTrace();
}finally{
if(database != null){
database.close();
}
}
return flag;
}

@Override
public boolean deletePerson(Object[] values) {
Log.i(TAG, "-->deletePerson");
boolean flag = false;
SQLiteDatabase database = null;
try {
String sql = "delete from person where id = ? ";
database = helper.getWritableDatabase();
database.execSQL(sql, values);
flag = true;
Log.i(TAG, "-->deletePerson"+ flag);
} catch (Exception e) {
e.printStackTrace();
}finally{
if(database != null){
database.close();
}
}
return flag;
}

@Override
public boolean updatePerson(Object[] values) {
Log.i(TAG, "-->updatePerson");
boolean flag = false;
SQLiteDatabase database = null;
try {
String sql = "update person set name = ?, address = ?, sex = ? where id = ? ";
database = helper.getWritableDatabase();
database.execSQL(sql, values);
flag = true;
Log.i(TAG, "-->updatePerson"+ flag);
} catch (Exception e) {
e.printStackTrace();
}finally{
if(database != null){
database.close();
}
}
return flag;
}

@Override
public Map<String, String> findPerson(String[] selectionArgs) {
Log.i(TAG, "-->findPerson begin");
Map<String, String> map = new HashMap<String, String>();
SQLiteDatabase database = null;
Cursor cursor = null;
try {
String sql = "select * from person where id = ? ";
database = helper.getWritableDatabase();
cursor = database.rawQuery(sql, selectionArgs);
int count = cursor.getColumnCount();
while (cursor.moveToNext()) {
for(int i=0; i<count; 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);
}
}

Log.i(TAG, "-->findPerson over"+map.toString());
} catch (Exception e) {
e.printStackTrace();
}finally{
if(database != null){
database.close();
}
}
return map;
}

@Override
public List<Map<String, String>> listPerson(String[] selectionArgs) {
Log.i(TAG, "listPerson run");
List<Map<String, String>> list = new ArrayList<Map<String,String>>();
SQLiteDatabase database = null;
Cursor cursor = null;
try {
String sql = "select * from person ";
database = helper.getWritableDatabase();
cursor = database.rawQuery(sql, selectionArgs);
int count = cursor.getColumnCount();
while(cursor.moveToNext()){
Map<String, String> map = new HashMap<String, String>();
for(int i = 0 ;i < count; 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) {
e.printStackTrace();
}finally{
if(database != null){
database.close();
}
}
return list;
}

}

View Code
四、在MyTest中添加测试代码，全部代码如下

package com.bruce.db_test.test;

import java.util.List;
import java.util.Map;

import com.bruce.dao.PersonDao;
import com.bruce.db_test.db.DbOpenHelper;
import com.bruce.db_test.service.PersonService;

import android.test.AndroidTestCase;
import android.util.Log;

public class MyTest extends AndroidTestCase {
private String TAG = "MyTest";
public void dbCreateTest(){
Log.i(TAG, "test begin");
DbOpenHelper helper = new DbOpenHelper(getContext());
helper.getWritableDatabase();
Log.i(TAG, "test end");
}

public void addPersonTest(){
PersonService service = new PersonDao(getContext());
Object[] values = {"奥巴马","美国","男"};
boolean flag = service.insertPerson(values);
Log.i(TAG, "--->addPerson" + flag);
}

public void deletePersonTest(){
PersonService service = new PersonDao(getContext());
Object[] values = {"2"};
boolean flag = service.deletePerson(values);
Log.i(TAG, "--->test-deletePerson" + flag);
}

public void updatePersonTest(){
PersonService service = new PersonDao(getContext());
Object[] values = {"刘德华","北京","男","1"};
boolean flag = service.updatePerson(values);
Log.i(TAG, "--->test-updatePerson" + flag);
}

public void viewPersonTest(){
PersonService service = new PersonDao(getContext());
String[] selectionArgs = {"1"};
Map<String, String> map = service.findPerson(selectionArgs);
Log.i(TAG, "-->test "+ map.toString());

}

public void listPersonTest(){
Log.i(TAG, "listPerosn begin");
PersonService service = new PersonDao(getContext());
//String[] selectionArgs = {null};
List<Map<String, String>> list = service.listPerson(null);
Log.i(TAG, "-->"+list.toString());
}
}

这是自己写SQL语句来实现的方法，后面介绍使用系统API来实现。