Android之数据库

2

3 ?import android.content.ContentValues;

4 ?import android.content.Context;

5
import android.database.Cursor;

6
import android.database.SQLException;

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import android.database.sqlite.SQLiteDatabase;

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import android.database.sqlite.SQLiteOpenHelper;

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import android.util.Log;

10

11
/**

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*

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* @author zhangjie

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*

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* 数据库相关操作的类

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*/

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public
class DBAdapter {

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/**

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* 数据库名

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*/

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private
static
final String DATABASE_NAME = "quickdial.db";

22

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/**

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* 数据表名

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*/

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private
static
final String DATABASE_TABLE = "quickdial";

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/**

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* 数据库版本

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*/

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private
static
final
int DATABASE_VERSION = 1;

32

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/**

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* key_id ：主键

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*/

36 @SuppressWarnings("unused")

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private
static
final String KEY_ID = "key_id";

38

39
/**

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* position ：位置信息，表示数据是第几项

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*/

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private
static
final String POSITION = "position";

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/**

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* name ：姓名

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*/

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private
static
final String NAME = "name";

48

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/**

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* phone_number ：电话号码

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*/

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private
static
final String PHONE_NUMBER = "phone_number";

53

54
/**

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* ip ：是否ip播出

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*/

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private
static
final String IP = "ip";

58

59
/**

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*

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*/

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private
static
final String DATABASE_CREATE =

63 "create table quickdial (key_id INTEGER PRIMARY KEY, "

64 + "position INTEGER, "

65 + "name TEXT, "

66 + "phone_number TEXT, "

67 + "ip INTEGER"

68 + ");";

69

70
/**

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*

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*/

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private
final Context context;

74

75
/**

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*

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*/

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private DatabaseHelper DBHelper;

79

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/**

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*

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*/

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private SQLiteDatabase db;

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public DBAdapter(Context ctx) {

86 context = ctx;

87 DBHelper = new DatabaseHelper(context);

88

89

90 }

91

92
private
static
class DatabaseHelper extends SQLiteOpenHelper {

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public DatabaseHelper(Context context) {

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super(context, DATABASE_NAME, null, DATABASE_VERSION);

95 }

96

97 @Override

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public
void onCreate(SQLiteDatabase db) {

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// TODO Auto-generated method stub

100 db.execSQL(DATABASE_CREATE);

101 }

102

103 @Override

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public
void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

105
// TODO Auto-generated method stub

106 db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);

107 onCreate(db);

108 }

109

110 }

111

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/**

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* 打开数据库

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* @return

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* @throws SQLException

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*/

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public SQLiteDatabase open() throws SQLException

118 {

119 db = DBHelper.getWritableDatabase();

120

121 Cursor cursor = getAll();

122

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if(cursor.getCount() == 0) {

124

125 Log.e("数据库为空", "插入数据");

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/**

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* 先使用假数据初始化数据库

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*/

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for(int i = 0; i < 10; i++) {

130 insert(i, "", "", 0);

131 }

132 } else {

133 Log.e("数据库不为空", "读取数据");

134 }

135 cursor.close();

136

137
return db;

138 }

139

140
/**

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* 关闭数据库

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*/

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public
void close()

144 {

145 DBHelper.close();

146 }

147

148
/**

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* 向数据库中插入数据

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*/

151

152
public
long insert(int position, String name, String phone_number, int ip) {

153

154 ContentValues initialValues = new ContentValues();

155 initialValues.put(POSITION, position);

156 initialValues.put(NAME, name);

157 initialValues.put(PHONE_NUMBER, phone_number);

158 initialValues.put(IP, ip);

159

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return db.insert(DATABASE_TABLE, null, initialValues);

161 }

162

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/**

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* 删除数据,其实不是真正意义上的删除，而是将name = ""、phone_number = ""、ip = 0

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*/

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public
boolean delete(int position) {

167

168 ContentValues initialValues = new ContentValues();

169 initialValues.put(POSITION, position);

170 initialValues.put(NAME, "");

171 initialValues.put(PHONE_NUMBER, "");

172 initialValues.put(IP, 0);

173

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return db.update(DATABASE_TABLE, initialValues, POSITION + "=" + position, null) > 0;

175

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// return db.delete(DATABASE_TABLE, POSITION + "=" + position, null) > 0;

177 }

178

179
/**

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* 更改数据

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*/

182
public
boolean update(int position, String name, String phone_number, int ip) {

183

184 ContentValues initialValues = new ContentValues();

185
//initialValues.put(POSITION, position);

186 initialValues.put(NAME, name);

187 initialValues.put(PHONE_NUMBER, phone_number);

188 initialValues.put(IP, ip);

189

190
return db.update(DATABASE_TABLE, initialValues, POSITION + "=" + position, null) > 0;

191 }

192

193
public Cursor getAll() {

194

195 Cursor cur = db.query(DATABASE_TABLE,

196
null, null, null, null, null, null);

197
return cur;

198

199 }

200

201
public Cursor get(long rowId) throws SQLException {

202 Cursor cur = db.query(true, DATABASE_TABLE, new String[] {POSITION,

203 NAME,

204 PHONE_NUMBER,

205 IP},

206

207 POSITION + "=" + rowId, null, null, null, null, null);

208

209
if(cur != null) {

210 cur.moveToFirst();

211 }

212

213
return cur;

214 }

215

216 }

2

3 m_DBAdapter = new DBAdapter(this);

4 m_DBAdapter.open();