1.创建一个类继承SQLiteOpenHelper（若使用SQLite）:
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public
class
MySQLiteHelper
extends
SQLiteOpenHelper
{
//重写构造方法
public
MySQLiteHelper(Context context, String name, CursorFactory factory,
int
version)
{
super
(context, name, factory, version);
}
//创建表
@Override
public
void
onCreate(SQLiteDatabase db)
{
db.execSQL(
"CREATE TABLE person(personid INTEGER PRIMARY KEY AUTOINCREMENT,name VARCHAR(20),phone VARCHAR(20))"
);
}
//升级表（当Database的Version低于当前new里的Version，直接执行下面方法）
@Override
public
void
onUpgrade(SQLiteDatabase db,
int
oldVersion,
int
newVersion)
{
int
v = newVersion - oldVersion;
if
(v >
0
)
{
db.execSQL(
"ALTER TABLE person ADD salary3 VARCHAR(20)"
);
}
}
}
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2.创建自定义ContentProvider：
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public
class
MyContentProvider
extends
ContentProvider
{
private
MySQLiteHelper mDBHelper;
public
MyContentProvider()
{
}
@Override
public
int
delete(Uri uri, String selection, String[] selectionArgs)
{
SQLiteDatabase db = mDBHelper.getWritableDatabase();
int
i = db.delete(
"person"
, selection,selectionArgs);
return
i;
}
@Override
public
String getType(Uri uri)
{
throw
new
UnsupportedOperationException(
"Not yet implemented"
);
}
//创建Uri
private
static
final
Uri URI = Uri.parse(
"content://com.example.cpone"
);
@Override
//插入
public
Uri insert(Uri uri, ContentValues values)
{
SQLiteDatabase db = mDBHelper.getWritableDatabase();
long
id = db.insert(
"person"
,
null
, values);
return
ContentUris.withAppendedId(URI, id);
//相当于原先的Uri加上插入的行号
}
@Override
public
boolean
onCreate()
//创建表
{
mDBHelper =
new
MySQLiteHelper(getContext(),
"person"
,
null
,
1
);
return
false
;
}
@Override
//查询
public
Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder)
{
SQLiteDatabase db = mDBHelper.getWritableDatabase();
Cursor cursor = db.query(
"person"
, projection, selection, selectionArgs,
null
,
null
, sortOrder);
return
cursor;
}
@Override
//修改
public
int
update(Uri uri, ContentValues values, String selection,
String[] selectionArgs)
{
SQLiteDatabase db = mDBHelper.getWritableDatabase();
int
i = db.update(
"person"
, values, selection, selectionArgs);
return
i;
}
}
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3.在另一个项目里使用自定义ContentProvider：
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public
class
MyContentProvider
extends
ContentProvider
{
private
MySQLiteHelper mDBHelper;
public
MyContentProvider()
{
}
@Override
public
int
delete(Uri uri, String selection, String[] selectionArgs)
{
SQLiteDatabase db = mDBHelper.getWritableDatabase();
int
i = db.delete(
"person"
, selection,selectionArgs);
return
i;
}
@Override
public
String getType(Uri uri)
{
throw
new
UnsupportedOperationException(
"Not yet implemented"
);
}
//创建Uri
private
static
final
Uri URI = Uri.parse(
"content://com.example.cpone"
);
@Override
//插入
public
Uri insert(Uri uri, ContentValues values)
{
SQLiteDatabase db = mDBHelper.getWritableDatabase();
long
id = db.insert(
"person"
,
null
, values);
return
ContentUris.withAppendedId(URI, id);
//相当于原先的Uri加上插入的行号
}
@Override
public
boolean
onCreate()
//创建表
{
mDBHelper =
new
MySQLiteHelper(getContext(),
"person"
,
null
,
1
);
return
false
;
}
@Override
//查询
public
Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder)
{
SQLiteDatabase db = mDBHelper.getWritableDatabase();
Cursor cursor = db.query(
"person"
, projection, selection, selectionArgs,
null
,
null
, sortOrder);
return
cursor;
}
@Override
//修改
public
int
update(Uri uri, ContentValues values, String selection,
String[] selectionArgs)
{
SQLiteDatabase db = mDBHelper.getWritableDatabase();
int
i = db.update(
"person"
, values, selection, selectionArgs);
return
i;
}
}
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注：
1.ContentProvider仍在主线程上运行，但对他的调用是异步的，不使用消息队列。
本文转自 glblong 51CTO博客，原文链接：http://blog.51cto.com/glblong/1217552，如需转载请自行联系原作者
