GreenDao 3.3.0 增删改查的使用（三）
GreenDao 3.3.0 基本使用与入门（一）
GreenDao 3.3.0 多表关联使用（二）
GreenDao 3.3.0 增删改查的使用（三）
GreenDao 的数据操作处理是继承自AbstractDao这个抽象类
最基本的函数：
- insert(T) delete(T) update(T) save(T) insertOrReplace(T) loadAll()
- 其中 save(T) 和insertOrReplace(T) 方法比较特殊既能进行插入操作也能执行修改操作
- insertInTx(T…) deleteInTx(T…) updateInTx(T…) saveInTx(T…) insertOrReplaceInTx(T…)
- refresh(T) 刷新数据
注意：在这函数后面有InTx(T…),是表示开启事物进行多个数据的操作
/**
* Inserts the given entities in the database using a transaction.
*
* @param entities The entities to insert.
*/
public void insertInTx(T... entities) {
insertInTx(Arrays.asList(entities), isEntityUpdateable());
}
/**
* Inserts the given entities in the database using a transaction. The given entities will become tracked if the PK
* is set.
*
* @param entities The entities to insert.
* @param setPrimaryKey if true, the PKs of the given will be set after the insert; pass false to improve
* performance.
*/
public void insertInTx(Iterable entities, boolean setPrimaryKey) {
DatabaseStatement stmt = statements.getInsertStatement();
executeInsertInTx(stmt, entities, setPrimaryKey);
}
private void executeInsertInTx(DatabaseStatement stmt, Iterable entities, boolean setPrimaryKey) {
db.beginTransaction();
try {
synchronized (stmt) {
if (identityScope != null) {
identityScope.lock();
}
try {
if (isStandardSQLite) {
SQLiteStatement rawStmt = (SQLiteStatement) stmt.getRawStatement();
for (T entity : entities) {
bindValues(rawStmt, entity);
if (setPrimaryKey) {
long rowId = rawStmt.executeInsert();
updateKeyAfterInsertAndAttach(entity, rowId, false);
} else {
rawStmt.execute();
}
}
} else {
for (T entity : entities) {
bindValues(stmt, entity);
if (setPrimaryKey) {
long rowId = stmt.executeInsert();
updateKeyAfterInsertAndAttach(entity, rowId, false);
} else {
stmt.execute();
}
}
}
} finally {
if (identityScope != null) {
identityScope.unlock();
}
}
}
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
}
save 和 insertOrReplace 区别
save it will be inserted (key is null) or updated (key is not null)
有key的对象执行更新，无key的执行插入
当对象有key但并不在数据库时会执行失败.适用于保存本地列表
/**
* "Saves" an entity to the database: depending on the existence of the key property, it will be inserted
* (key is null) or updated (key is not null).
*
* This is similar to {@link #insertOrReplace(Object)}, but may be more efficient, because if a key is present,
* it does not have to query if that key already exists.
*/
public void save(T entity) {
if (hasKey(entity)) {
update(entity);
} else {
insert(entity);
}
}
insertOrReplace
传入的对象在数据库中，有则更新无则插入,源码显示带有事物和线程
推荐同步数据库时使用该方法
/**
* Insert an entity into the table associated with a concrete DAO.
*
* @return row ID of newly inserted entity
*/
public long insertOrReplace(T entity) {
return executeInsert(entity, statements.getInsertOrReplaceStatement(), true);
}
private long executeInsert(T entity, DatabaseStatement stmt, boolean setKeyAndAttach) {
long rowId;
if (db.isDbLockedByCurrentThread()) {
rowId = insertInsideTx(entity, stmt);
} else {
// Do TX to acquire a connection before locking the stmt to avoid deadlocks
db.beginTransaction();
try {
rowId = insertInsideTx(entity, stmt);
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
}
if (setKeyAndAttach) {
updateKeyAfterInsertAndAttach(entity, rowId, true);
}
return rowId;
}
QueryBuilder 构建查询语
支持函数查询条件 distinct、 where 、whereOr 、or 、and、 OrderAsc/Desc、 join、 limit/offset(分页两个合用) 等具体查看QueryBuilder API
构建对象 CursorQuery buildCursor()、List list()、 T unique()、 T uniqueOrThrow()、 DeleteQuery buildDelete() 等
Property 配置where 条件判断
- eq()：==
- noteq()：!= ,"<>?"
- gt()： >
- lt()：<
- ge：>=
- le:<=
- like()：包含
- between：俩者之间
- in：在某个值内
- notIn：不在某个值内
- isNull: is null
- isNotNull: is not null
分页查询
- limit(int): 限制查询的数量;
- offset(int): 每次返回的数量; offset不能单独使用;
查询与LazyList类
Query ： Query类表示一个查询能够执行很多次;而当通过QueryBuilder的任何查询方法（eg:list()）来获取查询结果时，querybuilder都会 在其内部创建Query来执行查询语句的;如果执行多次查询应该使用Query对象; 如果只想获取一个结果时可以使用Query(or QueryBuilder)中的unique()方法;
LazyList : 可以通过以下方法获取查询结果集合；
list() 缓存查询结果;list()类型一般为ArrayList
listLazy() 懒查询,只有当调用list()中的实体对象时才会执行查询操作并且只缓存第一次被查询的结果，需要关闭
listlazyUncached() 懒查询,只有当调用list()中的实体对象时才会执行查询操作并且不缓存;
listIterator() 对查询结果进行遍历，不缓存，需要关闭;后面三个类是LazyList中的方法，LazyList为了执行不同的缓存策略其内部持有数据库的cursor对象；一般情况下这三个方法执行完毕后会自动关闭cursor；但是防止在还没有执行完查询结果时，对象被终结cursor还是无法被关闭的情况发生，需要手动关闭close();
getDaoSession/getDatabase 开启事物处理
getDatabase 开启
Database database = getDaoSession().getMessageEntityDao().getDatabase();
Cursor cursor = null;
ArrayList dataList = new ArrayList();
try {
database.beginTransaction();
cursor = database.rawQuery(sql, null);
while (cursor.moveToNext()) {
MessageEntity data = createMessageEntity(cursor);
dataList.add(data);
}
database.setTransactionSuccessful();
} catch (Exception e) {
LogUtil.e(TAG, "QueryMessageEntity " + e);
} finally {
if (database != null)
database.endTransaction();
if (null != cursor) {
cursor.close();
}
}
getDaoSession 开启
/**
* Calls the given Callable inside a database transaction and returns the result of the Callable. If you don't
* except a result, consider runInTx.
*/
public V callInTx(Callable callable) throws Exception {
db.beginTransaction();
try {
V result = callable.call();
db.setTransactionSuccessful();
return result;
} finally {
db.endTransaction();
}
}
callInTx 事物处理 执行查询操作
/**
* @param type -1：设备账户 ，0：app主账户，1：app一般账户
* @return
*/
public synchronized ArrayList getUserData(final int type) {
ArrayList userList = null;
try {
userList = (ArrayList) getDaoSession().callInTx(new Callable>() {
@Override
public List call() {
return getDaoSession().getAccountInformationDao().queryBuilder()
.where(AccountInformationDao.Properties.UserType.eq(type))
.build()
.list();
}
});
} catch (Exception e) {
LogUtil.e(TAG, "getUserData " + e);
}
return userList;
}
getDaoSession runInTx 开启线程处理
* Run the given Runnable inside a database transaction. If you except a result, consider callInTx.
*/
public void runInTx(Runnable runnable) {
db.beginTransaction();
try {
runnable.run();
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
}
insertOrReplace 新增或修改数据
/**
* 增加或修改用户信息
*
* @param
* @return
*/
public synchronized boolean setUserData(AccountInformation entity) {
try {
AccountInformationDao dao = getDaoSession().getAccountInformationDao();
AccountInformation user = dao.queryBuilder()
.where(AccountInformationDao.Properties.UserId.eq(entity.getUserId()))
.build()
.unique();
if (user != null) {
entity.setId(user.getId());
}
dao.insertOrReplace(entity);
dao.refresh(entity);
return true;
} catch (Exception e) {
LogUtil.e(TAG, "setUserData " + e);
return false;
}
}
QueryBuilder 切换条件执行查询语句
public synchronized ArrayList QueryUrlInfomationList(final int type, final int commandType, final String url, final long recordId, final int isUpload, final long createTime) {
ArrayList dataList = null;
try {
dataList = (ArrayList) getDaoSession().callInTx(new Callable>() {
@Override
public List call() throws Exception {
UrlInformationDao dao = getDaoSession().getUrlInformationDao();
QueryBuilder queryBuilder = dao.queryBuilder();
if (type == 1) {
queryBuilder.where(UrlInformationDao.Properties.CommentType.eq(commandType));
} else if (type == 5) {
queryBuilder.where(UrlInformationDao.Properties.CommentType.eq(commandType),
UrlInformationDao.Properties.CreateTime.eq(createTime)
);
} else if (type == 6) {
/* sql = "select * from " + Provider.UrlInformation.TABLE_NAME+ " where "
+ Provider.UrlInformation.commentType + " = '"+ commandType + "'"
+ " and "+ Provider.UrlInformation.url +"<>'' and '"
+url +"' LIKE '%'||"+Provider.UrlInformation.url + "||'%'";*/
queryBuilder.where(UrlInformationDao.Properties.CommentType.eq(commandType),
UrlInformationDao.Properties.Url.like("%" + url + "%"));
}
return queryBuilder.build().list();
}
});
} catch (Exception e) {
LogUtil.e(TAG, "QueryUrlInfomationList " + e);
}
return dataList;
执行SQL语句
rawQuery queryRawCreate execSQL
public long queryUserMaxId() {
long id=0;
try {
UsersDao userDao = getDaoSession().getUsersDao();
String sql = "select max("+UsersDao.Properties.Id.columnName+") "+UsersDao.Properties.Id.columnName+" from " + UsersDao.TABLENAME;
sql = "select max(_id) as maxId"+" from " + UsersDao.TABLENAME;
// sql="select * from "+UserDao.TABLENAME;
Cursor cursor = userDao.getDatabase().rawQuery(sql, null);
if (cursor.moveToNext()){//moveToNext moveToLast
//id = cursor.getLong(cursor.getColumnIndex(UserDao.Properties.Id.columnName));
id = cursor.getLong(cursor.getColumnIndex("maxId"));
Log.d(TAG,"queryUserMaxId cursor users id="+id);
}
cursor.close();
return id;
} catch (Exception e) {
e.printStackTrace();
Log.d(TAG,"queryUserMaxId cursor Exception"+e);
}
return 0;
}
QueryBuilder buildDelete 带事物删除
适用于数据量比较大批量删除
/**
* Builds a reusable query object for deletion (Query objects can be executed more efficiently than creating a
* QueryBuilder for each execution.
*/
public DeleteQuery buildDelete() {
if (!joins.isEmpty()) {
throw new DaoException("JOINs are not supported for DELETE queries");
}
String tablename = dao.getTablename();
String baseSql = SqlUtils.createSqlDelete(tablename, null);
StringBuilder builder = new StringBuilder(baseSql);
// tablePrefix gets replaced by table name below. Don't use tableName here because it causes trouble when
// table name ends with tablePrefix.
appendJoinsAndWheres(builder, tablePrefix);
String sql = builder.toString();
// Remove table aliases, not supported for DELETE queries.
// TODO(?): don't create table aliases in the first place.
sql = sql.replace(tablePrefix + ".\"", '"' + tablename + "\".\"");
checkLog(sql);
return DeleteQuery.create(dao, sql, values.toArray());
}
/**
* 删除所有家长端用户
*
* @param
* @return
*/
public synchronized boolean deleteUserByType() {
try {
getDaoSession().getAccountInformationDao().queryBuilder()
.where(AccountInformationDao.Properties.UserType.gt(-1))
.buildDelete().executeDeleteWithoutDetachingEntities();
return true;
} catch (Exception e) {
LogUtil.e(TAG, "deleteUserByType " + e);
return false;
}
}
Query SQL 查询
QueryBuilder>build()
Query对象一旦生成就能多次被使用，你也可以为下一次查询增加查询条件
Query query = userDao.queryBuilder().where( new
StringCondition("_ID IN " + "(SELECT USER_ID FROM
USER WHERE READ_ID = 0)")).build();
//分组查询
Query query = userDao.queryRawCreate( ", GROUP G WHERE
G.NAME=? AND T.GROUP_ID=G._ID", "admin");
Query query = userDao.queryBuilder().where(
userDao.Properties.IsRead.gt(0),
userDao.Properties.DistinctName.eq("yes")).build();
List userFirst = query.list();
query.setParameter(0, 1);
query.setParameter(1, "no");
List userSecond = query.list();
自定义SQL 拼接多个查询语句
/**
* 聊天消息查询
*
* @param type 1： 根据messaId查询，2：查询所有消息，3：群消息根据时间查询（大于），4：群消息根据时间查询（小于）,5：私聊消息根据时间查询（大于），
* 6：私聊消息根据时间查询（小于）,7：当前消息根据时间查询（大于），6：当前消息根据时间查询（小于）
* @param messageId 消息Id 传私人Id为私聊消息，传群Id,为群聊消息
* @param time 时间
* @param order 只能传 DESC(由大到小)和ASC(由小到大)
* @param size 查询数据的数量
* @return
* @userId userId：自己用户id
* @groupId 私聊方Id或群id
*/
public synchronized ArrayList QueryMessageList(int type, long messageId, long userId, long reuserid, String time, int size, String order) {
String sql = null;
Database database = getDaoSession().getMessageEntityDao().getDatabase();
if (type == 1) {
sql = "select * from " + MessageEntityDao.TABLENAME
+ " where " + MessageEntityDao.Properties.MessageId.columnName + " = '" + messageId + "'";
} else if (type == 2) {
sql = "select * from " + MessageEntityDao.TABLENAME;
} else if (type == 3) {
sql = "select * from " + MessageEntityDao.TABLENAME
+ " where " + MessageEntityDao.Properties.ReuserId.columnName + " = '" + reuserid + "'"
+ " and " + MessageEntityDao.Properties.CreateTime.columnName + " > '" + time + "'"
+ " order by " + MessageEntityDao.Properties.CreateTime.columnName + " " + order + " limit '" + size + "' offset '" + 0 + "'";
} else if (type == 4) {
sql = "select * from " + MessageEntityDao.TABLENAME
+ " where " + MessageEntityDao.Properties.ReuserId.columnName + " = '" + reuserid + "'"
+ " and " + MessageEntityDao.Properties.CreateTime.columnName + " < '" + time + "'"
+ " order by " + MessageEntityDao.Properties.CreateTime.columnName + " " + order + " limit '" + size + "' offset '" + 0 + "'";
} else if (type == 5) {
sql = "select * from '" + MessageEntityDao.TABLENAME + "'" + " where "
+ " ( " + " ( " + MessageEntityDao.Properties.UserId.columnName + " = '" + reuserid + "' and "
+ MessageEntityDao.Properties.ReuserId.columnName + " = '" + userId + "' ) " + " or "
+ " ( " + MessageEntityDao.Properties.UserId.columnName + " = '" + userId + "' and "
+ MessageEntityDao.Properties.ReuserId.columnName + " = '" + reuserid + "' ) " + " ) "
+ " and " + MessageEntityDao.Properties.CreateTime.columnName + " > '" + time + "'"
+ " order by " + MessageEntityDao.Properties.CreateTime.columnName + " " + order + " limit '" + size + "' offset '" + 0 + "'";
} else if (type == 6) {
sql = "select * from '" + MessageEntityDao.TABLENAME + "'" + " where "
+ " ( " + " ( " + MessageEntityDao.Properties.UserId.columnName + " = '" + reuserid + "' and "
+ MessageEntityDao.Properties.ReuserId.columnName + " = '" + userId + "' ) " + " or "
+ " ( " + MessageEntityDao.Properties.UserId.columnName + " = '" + userId + "' and "
+ MessageEntityDao.Properties.ReuserId.columnName + " = '" + reuserid + "' ) " + " ) "
+ " and " + MessageEntityDao.Properties.CreateTime.columnName + " < '" + time + "'"
+ " order by " + MessageEntityDao.Properties.CreateTime.columnName + " " + order + " limit '" + size + "' offset '" + 0 + "'";
} else if (type == 7) {
sql = "select * from '" + MessageEntityDao.TABLENAME + "'" + " where "
+ MessageEntityDao.Properties.CreateTime.columnName + " > '" + time + "'"
+ " order by " + MessageEntityDao.Properties.CreateTime.columnName + " " + order + " limit '" + size + "' offset '" + 0 + "'";
} else if (type == 8) {
sql = "select * from messagelist t where EXISTS ( select 1 from messagelist GROUP BY distinctName HAVING MAX(_id) = t._id)"
+ " and " + MessageEntityDao.Properties.CreateTime.columnName + " < '" + time + "'"
+ " order by " + MessageEntityDao.Properties.CreateTime.columnName + " " + order + " limit '" + size + "' offset '" + 0 + "'";
//+Provider.MessageEntity.commenType + " = '" + comment + "'"
//SELECT * FROM test_table t WHERE EXISTS ( SELECT 1 FROM test_table GROUP BY uname HAVING MAX(id) = t.id )
}
LogUtil.d(TAG, "QueryMessageEntity ,sql:" + sql);
Cursor cursor = null;
ArrayList dataList = new ArrayList();
try {
database.beginTransaction();
cursor = database.rawQuery(sql, null);
while (cursor.moveToNext()) {
MessageEntity data = createMessageEntity(cursor);
dataList.add(data);
}
database.setTransactionSuccessful();
} catch (Exception e) {
LogUtil.e(TAG, "QueryMessageEntity " + e);
} finally {
if (database != null)
database.endTransaction();
if (null != cursor) {
cursor.close();
}
}
return dataList;
}
/**
* 创建消息实体
*
* @param cursor
* @return
*/
public MessageEntity createMessageEntity(Cursor cursor) {
MessageEntity data = new MessageEntity();
data.setChatType(cursor.getInt(cursor.getColumnIndex(MessageEntityDao.Properties.ChatType.columnName)));
data.setMessageId(cursor.getLong(cursor.getColumnIndex(MessageEntityDao.Properties.MessageId.columnName)));
data.setMessageType(cursor.getInt(cursor.getColumnIndex(MessageEntityDao.Properties.MessageType.columnName)));
data.setUserId(cursor.getLong(cursor.getColumnIndex(MessageEntityDao.Properties.UserId.columnName)));
data.setUserName(cursor.getString(cursor.getColumnIndex(MessageEntityDao.Properties.UserName.columnName)));
data.setUserPic(cursor.getString(cursor.getColumnIndex(MessageEntityDao.Properties.UserPic.columnName)));
data.setReuserId(cursor.getLong(cursor.getColumnIndex(MessageEntityDao.Properties.ReuserId.columnName)));
data.setReuserName(cursor.getString(cursor.getColumnIndex(MessageEntityDao.Properties.ReuserName.columnName)));
data.setReuserPic(cursor.getString(cursor.getColumnIndex(MessageEntityDao.Properties.ReuserPic.columnName)));
data.setMcontent(cursor.getString(cursor.getColumnIndex(MessageEntityDao.Properties.Mcontent.columnName)));
data.setCreateTime(cursor.getString(cursor.getColumnIndex(MessageEntityDao.Properties.CreateTime.columnName)));
data.setIsRead(cursor.getInt(cursor.getColumnIndex(MessageEntityDao.Properties.IsRead.columnName)));
data.setIsSend(cursor.getInt(cursor.getColumnIndex(MessageEntityDao.Properties.IsSend.columnName)));
data.setMessageSize(cursor.getInt(cursor.getColumnIndex(MessageEntityDao.Properties.MessageSize.columnName)));
data.setSubCode(cursor.getInt(cursor.getColumnIndex(MessageEntityDao.Properties.SubCode.columnName)));
data.setSendType(cursor.getInt(cursor.getColumnIndex(MessageEntityDao.Properties.SendType.columnName)));
data.setReceType(cursor.getInt(cursor.getColumnIndex(MessageEntityDao.Properties.ReceType.columnName)));
data.setSubGroup(cursor.getInt(cursor.getColumnIndex(MessageEntityDao.Properties.SubGroup.columnName)));
data.setLocalityContent(cursor.getString(cursor.getColumnIndex(MessageEntityDao.Properties.LocalityContent.columnName)));
data.setDistinctName(cursor.getString(cursor.getColumnIndex(MessageEntityDao.Properties.DistinctName.columnName)));
return data;
}