记录一下sqllite的基本使用封装，使用时替换其中的部分代码即可
public class DBHelper {
private static DBConnection helper;
private static DBHelper dbHelper;
public static DBHelper getInstance(Context context)
{
if(dbHelper == null){
dbHelper = new DBHelper(context);
}
return dbHelper;
}
public DBHelper(Context context){
super();
getDB(context);
}
private static DBConnection getDB(Context context){
if(helper == null){
helper = new DBConnection(context);
}
return helper;
}
public void addManyPro(ArrayList<ChannelInfo> prolist)
{
SQLiteDatabase db = helper.getWritableDatabase();
db.beginTransaction();
for(int i = 0;i<prolist.size();i++)
{
ContentValues contentValues = new ContentValues();
contentValues.put(UserSchema.channel_id,prolist.get(i).getId());
contentValues.put(UserSchema.channel_name,prolist.get(i).getChannelName());
contentValues.put(UserSchema.group_name, prolist.get(i).getGroupName());
contentValues.put(UserSchema.url, prolist.get(i).getUrl());
db.insert(UserSchema.TABLE_NAME, null, contentValues);
}
db.setTransactionSuccessful();
db.endTransaction();
db.close();
}
public void addPro(ChannelInfo pro)
{
SQLiteDatabase db = helper.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(UserSchema.channel_id,pro.getId());
contentValues.put(UserSchema.channel_name,pro.getChannelName());
contentValues.put(UserSchema.group_name, pro.getGroupName());
contentValues.put(UserSchema.url, pro.getUrl());
db.insert(UserSchema.TABLE_NAME, null, contentValues);
db.close();
}
public void DropTable() {
SQLiteDatabase db = null;
try {
db = helper.getWritableDatabase();
String sql = "DROP TABLE " + UserSchema.TABLE_NAME;
db.execSQL(sql);
String create_sql = "CREATE TABLE link_info(id integer primary key autoincrement,channel_id integer,channel_name varchar(100),"
+ "url varchar(200),group_name varchar(50))";
db.execSQL(create_sql);
} catch (Exception ex) {
}
finally {
if(db!=null){
db.close();
}
}
}
public void DropDatabase(Context ctx, String DATABASE_NAME) {
try {
ctx.deleteDatabase(DATABASE_NAME);
} catch (Exception ex) {
}
}
public void update(ContentValues values, String where, String[] whereArgs) {
SQLiteDatabase db = helper.getWritableDatabase();
db.update(UserSchema.TABLE_NAME, values, where, whereArgs);
db.close();
}
public void delete(String where, String[] whereArgs) {
SQLiteDatabase db = helper.getWritableDatabase();
db.delete(UserSchema.TABLE_NAME, where, whereArgs);
db.close();
}
public void delDB(String DBName) {
SQLiteDatabase db = helper.getWritableDatabase();
db.execSQL("DROP Database " + DBName);
db.close();
}
public int queryChannelSize() {
int count = 0;
Cursor cursor = null;
SQLiteDatabase db = null;
try {
db = helper.getReadableDatabase();
cursor = db.rawQuery("select count(*)from link_info",null);
cursor.moveToFirst();
count = cursor.getInt(0);
}catch (Exception e){
e.printStackTrace();
}
finally {
if(cursor!=null){
cursor.close();
}
if(db!=null){
db.close();
}
}
return count;
}
public ArrayList<ChannelInfo> query() {
try {
final SQLiteDatabase db = helper.getReadableDatabase();
Cursor c = null;
/* c = db.query(UserSchema.TABLE_NAME, null, where, whereArgs, null,
null, orderBy, limit);*/
c = db.query(UserSchema.TABLE_NAME, new String[] {UserSchema.channel_id, UserSchema.channel_name,UserSchema.url,UserSchema.group_name },
null, null, null, null, null);
ArrayList<ChannelInfo> lst = new ArrayList<ChannelInfo>();
while (c != null && c.moveToNext()) {
ChannelInfo item = new ChannelInfo();
item.setId(c.getInt(c.getColumnIndex("channel_id")));
item.setChannelName(c.getString(c.getColumnIndex("channel_name")));
item.setUrl(c.getString(c.getColumnIndex("url")));
item.setGroupName(c.getString(c.getColumnIndex("group_name")));
lst.add(item);
}
if (c != null)c.close();
return lst;
} catch (Exception e) {
// TODO: handle exception
}
return null;
}
public ArrayList<String> queryChannelListName() {
ArrayList<String> channelList = new ArrayList<>();
try {
final SQLiteDatabase db = helper.getReadableDatabase();
Cursor c = null;
/* c = db.query(UserSchema.TABLE_NAME, null, where, whereArgs, null,
null, orderBy, limit);*/
c = db.query(UserSchema.TABLE_NAME, new String[] {UserSchema.channel_id, UserSchema.channel_name,UserSchema.url,UserSchema.group_name },
null, null, null, null, null);
ArrayList<ChannelInfo> lst = new ArrayList<ChannelInfo>();
while (c != null && c.moveToNext()) {
channelList.add(c.getString(c.getColumnIndex("channel_name")));
}
if (c != null)c.close();
return channelList;
} catch (Exception e) {
// TODO: handle exception
}
return null;
}
public ArrayList<String> queryGroupList() {
ArrayList<String> channelList = new ArrayList<>();
try {
final SQLiteDatabase db = helper.getReadableDatabase();
Cursor c = null;
/* c = db.query(UserSchema.TABLE_NAME, null, where, whereArgs, null,
null, orderBy, limit);*/
String sql = "SELECT DISTINCT group_name FROM link_info;";
c = db.rawQuery(sql,null);
while (c != null && c.moveToNext()) {
channelList.add(c.getString(c.getColumnIndex("group_name")));
}
if (c != null)c.close();
return channelList;
} catch (Exception e) {
// TODO: handle exception
}
return null;
}
public ArrayList<String> queryUrlList() {
ArrayList<String> channelList = new ArrayList<>();
try {
final SQLiteDatabase db = helper.getReadableDatabase();
Cursor c = null;
/* c = db.query(UserSchema.TABLE_NAME, null, where, whereArgs, null,
null, orderBy, limit);*/
c = db.query(UserSchema.TABLE_NAME, new String[] {UserSchema.channel_id, UserSchema.channel_name,UserSchema.url,UserSchema.group_name },
null, null, null, null, null);
ArrayList<ChannelInfo> lst = new ArrayList<ChannelInfo>();
while (c != null && c.moveToNext()) {
channelList.add(c.getString(c.getColumnIndex("url")));
}
if (c != null)c.close();
return channelList;
} catch (Exception e) {
// TODO: handle exception
}
return null;
}
public ArrayList<ChannelInfo> query(String groupName) {
try {
final SQLiteDatabase db = helper.getReadableDatabase();
Cursor c = null;
/* c = db.query(UserSchema.TABLE_NAME, null, where, whereArgs, null,
null, orderBy, limit);*/
String sql = "select * from link_info where group_name='"+groupName+"'";
Log.v("aaa", "channellist database sql : "+sql);
c = db.rawQuery(sql,null);
ArrayList<ChannelInfo> lst = new ArrayList<ChannelInfo>();
while (c != null && c.moveToNext()) {
ChannelInfo item = new ChannelInfo();
item.setId(c.getInt(c.getColumnIndex("channel_id")));
item.setChannelName(c.getString(c.getColumnIndex("channel_name")));
item.setUrl(c.getString(c.getColumnIndex("url")));
item.setGroupName(c.getString(c.getColumnIndex("group_name")));
lst.add(item);
}
if (c != null)c.close();
return lst;
} catch (Exception e) {
// TODO: handle exception
}
return null;
}
public interface UserSchema {
String TABLE_NAME = "link_info";
String channel_id = "channel_id";
String channel_name = "channel_name";
String group_name = "group_name";
String url = "url";
}
public static class DBConnection extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "netlink.db";
private static final int DATABASE_VERSION = 1;
private DBConnection(Context ctx) {
super(ctx, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String create_sql = "CREATE TABLE link_info(id integer primary key autoincrement,channel_id integer,channel_name varchar(100),"
+ "url varchar(200),group_name varchar(50))";
db.execSQL(create_sql);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
String sql=" DROP TABLE IF EXISTS "+UserSchema.TABLE_NAME;
db.execSQL(sql);
onCreate(db);
}
}
}