最近写了一个抽签值日的程序需要用到数据库来存储数据，如果放到数据库中还要建表，还需要连网，本人感觉没有必要，所以就选择了本地存储sqlite的方式，来记录一下，方便以后查看
先创建一个工具类DateBaseHelper
public class StuDBHelper extends SQLiteOpenHelper{
public final static String NAME_CONTEXT_TAL = "name_context";//项目表
public final static String NAME_PERSON_TAL = "person_context";//人员与项目对应表
public final static int DB_VERSION = 6;
public StuDBHelper(Context context) {
super(context, NAME_CONTEXT_TAL, null, DB_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
String sql = "create table if not exists " + NAME_CONTEXT_TAL + "(_id integer primary key autoincrement,context_id varchar, context_name varchar)";
db.execSQL(sql);
String personsql = "create table if not exists " + NAME_PERSON_TAL + "(_id integer primary key autoincrement,person_id varchar, person_name varchar,context_name varchar)";
db.execSQL(personsql);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
将数据插入到数据库中：
//将系统消息数据插入到本地数据库
public void insertmessge(){
if(messageList != null &&messageList.size() != 0){
helper = new StuDBHelper(ContentActivity.this);
SQLiteDatabase db = helper.getWritableDatabase();
//插入系统消息
for (int i = 0; i < messageList.size(); i++) {
ContentValues valuse = new ContentValues();
valuse.put("context_id",messageList.get(i).getContext_id() );
valuse.put("context_name",messageList.get(i).getContext_name());
db.insert(helper.NAME_CONTEXT_TAL,null, valuse);
}
db.close();
}
}
删除数据库中的数据：
helper = new StuDBHelper(ContentActivity.this);
SQLiteDatabase db = helper.getWritableDatabase();
db.delete(helper.NAME_CONTEXT_TAL,"context_id=?",newString[{basicDateEntity.getListstring().get(position).getContext_id()});
db.close();
修改数据库中的数据：
helper = new StuDBHelper(ContentActivity.this);
SQLiteDatabase db = helper.getWritableDatabase();
ContentValues value = new ContentValues();
value.put("code", pro.getCode());
value.put("name", pro.getName());
value.put("qty", pro.getQty());
db.update(helper.NAME_CONTEXT_TAL,value,"context_id=?","context_id=?",newString[{basicDateEntity.getListstring().get(position).getContext_id()})
db.close();
查询数据库中的数据（在这里我写了一个公共类）：
public class Countents {
Context context;
List<MessageEntity> message_list;
List<PersonMessageEntity> personmessage_list;
private static StuDBHelper helper;
public static SQLiteDatabase db;
public static Cursor cursor;
private String context_names;
private String context_ids;
private String person_contexts;
private String person_ids;
private String person_names;
BasicDateEntity basicDateEntity = BasicDateEntity.getSingle();
public Countents(Context context){
this.context = context;
}
public void SQLitedate(){
message_list = new ArrayList<MessageEntity>();
helper = new StuDBHelper(context);
// 通过数据库助手，创建数据库
db = helper.getReadableDatabase();
cursor = db.query(StuDBHelper.NAME_CONTEXT_TAL, null, null,null, null, null, null, null);
// 字段对应的索引值
int context_name = cursor.getColumnIndex("context_name");
int context_id = cursor.getColumnIndex("context_id");
// 遍历查询数据
while (cursor.moveToNext()) {
// 通过索引值间接获取字段对应的数据
context_names = cursor.getString(context_name);
context_ids = cursor.getString(context_id);
MessageEntity messagelist = new MessageEntity(context_names,context_ids);
message_list.add(messagelist);
}
basicDateEntity.setListstring(message_list);
db.close();
cursor.close();
}
public void SQLitedatePerson(){
personmessage_list = new ArrayList<PersonMessageEntity>();
helper = new StuDBHelper(context);
// 通过数据库助手，创建数据库
db = helper.getReadableDatabase();
cursor = db.query(StuDBHelper.NAME_PERSON_TAL, null, null,null, null, null, null, null);
// 字段对应的索引值
int person_context = cursor.getColumnIndex("context_name");
int person_name = cursor.getColumnIndex("person_name");
int person_id = cursor.getColumnIndex("person_id");
// 遍历查询数据
while (cursor.moveToNext()) {
// 通过索引值间接获取字段对应的数据
person_contexts = cursor.getString(person_context);
person_ids = cursor.getString(person_id);
person_names = cursor.getString(person_name);
PersonMessageEntity personmessage = new PersonMessageEntity(person_ids,person_names,person_contexts);
personmessage_list.add(personmessage);
}
basicDateEntity.setPersonlist(personmessage_list);
db.close();
cursor.close();
}
}
调用此类中方法就可以查询到数据
Countents countents = new Countents(ContentActivity.this);
//调用查询的方法
countents.SQLitedate();
}