sqlitehelper android,SQLite Helper工具类
通过这个类，可以实现对数据库的创建，表的创建以及增删改查等操作.
package com.cjq.baidu.map;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class LocationInfoUtil {
public SQLiteDatabase mSQLiteDatabase =
null;
private final static String DATABASE_NAME =
"mapforcjq.db";
private final static String TABLE_NAME =
"cjq";
private final static int DB_VERSION = 1;
private final static String KEY_ID =
"_id";
private final static String KEY_LATITUDE =
"latitude";
private final static String KEY_LONGITUDE =
"longitude";
private final static String KEY_TIME =
"dateandtime";
private final static String KEY_FIELD =
"field";
private final static String CREATE_TABLE =
"CREATE TABLE " + TABLE_NAME
+ " (" +
KEY_ID + " INTEGER PRIMARY KEY," + KEY_LATITUDE
+ " DOUBLE,"
+ KEY_LONGITUDE + " DOUBLE," + KEY_TIME
+ "
TIMESTAMP," + KEY_FIELD + " TEXT)";
不写类型
private final static String CREATE_TABLE = "CREATE TABLE " +
TABLE_NAME
+ " (" +
KEY_ID + " INTEGER PRIMARY KEY," + KEY_LATITUDE
+ "," +
KEY_LONGITUDE + "," + KEY_TIME
+ " ," +
KEY_FIELD + " TEXT)";
private DatabaseHelper mDatabaseHelper =
null;
private Context mContext = null;
private static class DatabaseHelper extends
SQLiteOpenHelper {
DatabaseHelper(Context context)
{
super(context,
DATABASE_NAME, null, DB_VERSION);
}
// 创建表
@Override
public void
onCreate(SQLiteDatabase db) {
db.execSQL(CREATE_TABLE);
}
// 升级数据库
@Override
public void
onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
db.execSQL("DROP
TABLE IF EXISTS notes");
onCreate(db);
}
}
public LocationInfoUtil(Context context)
{
mContext = context;
}
// 打开数据库，返回数据库对象
public void open() throws SQLException {
mDatabaseHelper = new
DatabaseHelper(mContext);
mSQLiteDatabase =
mDatabaseHelper.getWritableDatabase();
}
// 关闭数据库
public void close() {
mDatabaseHelper.close();
}
// 插入一条数据
public long insertData(long latitude, long
longitude, long time) {
ContentValues cv = new
ContentValues();
cv.put(KEY_LATITUDE,
latitude);
cv.put(KEY_LONGITUDE,
longitude);
cv.put(KEY_TIME, time);
return
mSQLiteDatabase.insert(TABLE_NAME, KEY_ID, cv);
}
// 删除一条数据
public boolean deleteData(long rowId) {
return
mSQLiteDatabase.delete(TABLE_NAME, KEY_ID + "=" + rowId, null)
> 0;
}
// 通过Cursor查询所有数据
public Cursor fetchAllData() {
return
mSQLiteDatabase.query(TABLE_NAME, new String[] { KEY_ID,
KEY_LATITUDE,
KEY_LONGITUDE, KEY_TIME }, null, null, null,
null,
null);
}
// 通过Cursor查询指定数据
public Cursor fetchData(long rowId) {
Cursor mCursor =
mSQLiteDatabase.query(TABLE_NAME, new String[] {
KEY_ID,
KEY_LATITUDE, KEY_LONGITUDE, KEY_TIME }, KEY_ID + "="
+
rowId, null, null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
public boolean updateData(long latitude, long
longitude, long time) {
ContentValues cv = new
ContentValues();
cv.put(KEY_LATITUDE,
latitude);
cv.put(KEY_LONGITUDE,
longitude);
return
mSQLiteDatabase.update(TABLE_NAME, cv, KEY_TIME + "=" + time,
null)
> 0;
}
}