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Mms数据库的triggers
1. threads表将SMS、MMS的信息组织成一个conversation，所以当MMS、SMS信息发生改变时也需要更新threads表
2. 维护pending_msgs表格，其中包含pending_msgs表用于存储待发送或下载的SMS/MMS
3. 维护错误标志位
/*** the name of the table that is used to store the queue of* messages(both MMS and SMS) to be sent/downloaded.*/public static final String TABLE_PENDING_MSG = "pending_msgs";
private void createCommonTriggers(SQLiteDatabase db) {// Updates threads table whenever a message is added to pdu.db.execSQL("CREATE TRIGGER pdu_update_thread_on_insert AFTER INSERT ON " +MmsProvider.TABLE_PDU + " " +PDU_UPDATE_THREAD_CONSTRAINTS +PDU_UPDATE_THREAD_DATE_SNIPPET_COUNT_ON_UPDATE);// Updates threads table whenever a message is added to sms.db.execSQL("CREATE TRIGGER sms_update_thread_on_insert AFTER INSERT ON sms " +SMS_UPDATE_THREAD_DATE_SNIPPET_COUNT_ON_UPDATE);// Updates threads table whenever a message in pdu is updated.db.execSQL("CREATE TRIGGER pdu_update_thread_date_subject_on_update AFTER" +" UPDATE OF " + Mms.DATE + ", " + Mms.SUBJECT + ", " + Mms.MESSAGE_BOX +" ON " + MmsProvider.TABLE_PDU + " " +PDU_UPDATE_THREAD_CONSTRAINTS +PDU_UPDATE_THREAD_DATE_SNIPPET_COUNT_ON_UPDATE);// Updates threads table whenever a message in sms is updated.db.execSQL("CREATE TRIGGER sms_update_thread_date_subject_on_update AFTER" +" UPDATE OF " + Sms.DATE + ", " + Sms.BODY + ", " + Sms.TYPE +" ON sms " +SMS_UPDATE_THREAD_DATE_SNIPPET_COUNT_ON_UPDATE);// Updates threads table whenever a message in pdu is updated.db.execSQL("CREATE TRIGGER pdu_update_thread_read_on_update AFTER" +" UPDATE OF " + Mms.READ +" ON " + MmsProvider.TABLE_PDU + " " +PDU_UPDATE_THREAD_CONSTRAINTS +"BEGIN " +PDU_UPDATE_THREAD_READ_BODY +"END;");// Updates threads table whenever a message in sms is updated.db.execSQL("CREATE TRIGGER sms_update_thread_read_on_update AFTER" +" UPDATE OF " + Sms.READ +" ON sms " +"BEGIN " +SMS_UPDATE_THREAD_READ_BODY +"END;");// Update threads table whenever a message in pdu is deleteddb.execSQL("CREATE TRIGGER pdu_update_thread_on_delete " +"AFTER DELETE ON pdu " +"BEGIN " +" UPDATE threads SET " +" date = (strftime('%s','now') * 1000)" +" WHERE threads._id = old." + Mms.THREAD_ID + "; " +UPDATE_THREAD_COUNT_ON_OLD +UPDATE_THREAD_SNIPPET_SNIPPET_CS_ON_DELETE +"END;");// As of DATABASE_VERSION 55, we've removed these triggers that delete empty threads.// These triggers interfere with saving drafts on brand new threads. Instead of// triggers cleaning up empty threads, the empty threads should be cleaned up by// an explicit call to delete with Threads.OBSOLETE_THREADS_URI.// // When the last message in a thread is deleted, these
// // triggers ensure that the entry for its thread ID is removed
// // from the threads table.
// db.execSQL("CREATE TRIGGER delete_obsolete_threads_pdu " +
// "AFTER DELETE ON pdu " +
// "BEGIN " +
// " DELETE FROM threads " +
// " WHERE " +
// " _id = old.thread_id " +
// " AND _id NOT IN " +
// " (SELECT thread_id FROM sms " +
// " UNION SELECT thread_id from pdu); " +
// "END;");
//
// db.execSQL("CREATE TRIGGER delete_obsolete_threads_when_update_pdu " +
// "AFTER UPDATE OF " + Mms.THREAD_ID + " ON pdu " +
// "WHEN old." + Mms.THREAD_ID + " != new." + Mms.THREAD_ID + " " +
// "BEGIN " +
// " DELETE FROM threads " +
// " WHERE " +
// " _id = old.thread_id " +
// " AND _id NOT IN " +
// " (SELECT thread_id FROM sms " +
// " UNION SELECT thread_id from pdu); " +
// "END;");// Insert pending status for M-Notification.ind or M-ReadRec.ind// when they are inserted into Inbox/Outbox.db.execSQL("CREATE TRIGGER insert_mms_pending_on_insert " +"AFTER INSERT ON pdu " +"WHEN new." + Mms.MESSAGE_TYPE + "=" + PduHeaders.MESSAGE_TYPE_NOTIFICATION_IND +" OR new." + Mms.MESSAGE_TYPE + "=" + PduHeaders.MESSAGE_TYPE_READ_REC_IND +" " +"BEGIN " +" INSERT INTO " + MmsSmsProvider.TABLE_PENDING_MSG +" (" + PendingMessages.PROTO_TYPE + "," +" " + PendingMessages.MSG_ID + "," +" " + PendingMessages.MSG_TYPE + "," +" " + PendingMessages.ERROR_TYPE + "," +" " + PendingMessages.ERROR_CODE + "," +" " + PendingMessages.RETRY_INDEX + "," +" " + PendingMessages.DUE_TIME + ") " +" VALUES " +" (" + MmsSms.MMS_PROTO + "," +" new." + BaseColumns._ID + "," +" new." + Mms.MESSAGE_TYPE + ",0,0,0,0);" +"END;");// Insert pending status for M-Send.req when it is moved into Outbox.db.execSQL("CREATE TRIGGER insert_mms_pending_on_update " +"AFTER UPDATE ON pdu " +"WHEN new." + Mms.MESSAGE_TYPE + "=" + PduHeaders.MESSAGE_TYPE_SEND_REQ +" AND new." + Mms.MESSAGE_BOX + "=" + Mms.MESSAGE_BOX_OUTBOX +" AND old." + Mms.MESSAGE_BOX + "!=" + Mms.MESSAGE_BOX_OUTBOX + " " +"BEGIN " +" INSERT INTO " + MmsSmsProvider.TABLE_PENDING_MSG +" (" + PendingMessages.PROTO_TYPE + "," +" " + PendingMessages.MSG_ID + "," +" " + PendingMessages.MSG_TYPE + "," +" " + PendingMessages.ERROR_TYPE + "," +" " + PendingMessages.ERROR_CODE + "," +" " + PendingMessages.RETRY_INDEX + "," +" " + PendingMessages.DUE_TIME + ") " +" VALUES " +" (" + MmsSms.MMS_PROTO + "," +" new." + BaseColumns._ID + "," +" new." + Mms.MESSAGE_TYPE + ",0,0,0,0);" +"END;");// When a message is moved out of Outbox, delete its pending status.db.execSQL("CREATE TRIGGER delete_mms_pending_on_update " +"AFTER UPDATE ON " + MmsProvider.TABLE_PDU + " " +"WHEN old." + Mms.MESSAGE_BOX + "=" + Mms.MESSAGE_BOX_OUTBOX +" AND new." + Mms.MESSAGE_BOX + "!=" + Mms.MESSAGE_BOX_OUTBOX + " " +"BEGIN " +" DELETE FROM " + MmsSmsProvider.TABLE_PENDING_MSG +" WHERE " + PendingMessages.MSG_ID + "=new._id; " +"END;");// Delete pending status for a message when it is deleted.db.execSQL("CREATE TRIGGER delete_mms_pending_on_delete " +"AFTER DELETE ON " + MmsProvider.TABLE_PDU + " " +"BEGIN " +" DELETE FROM " + MmsSmsProvider.TABLE_PENDING_MSG +" WHERE " + PendingMessages.MSG_ID + "=old._id; " +"END;");// TODO Add triggers for SMS retry-status management.// Update the error flag of threads when the error type of// a pending MM is updated.db.execSQL("CREATE TRIGGER update_threads_error_on_update_mms " +" AFTER UPDATE OF err_type ON pending_msgs " +" WHEN (OLD.err_type < 10 AND NEW.err_type >= 10)" +" OR (OLD.err_type >= 10 AND NEW.err_type < 10) " +"BEGIN" +" UPDATE threads SET error = " +" CASE" +" WHEN NEW.err_type >= 10 THEN error + 1" +" ELSE error - 1" +" END " +" WHERE _id =" +" (SELECT DISTINCT thread_id" +" FROM pdu" +" WHERE _id = NEW.msg_id); " +"END;");// Update the error flag of threads when delete pending message.db.execSQL("CREATE TRIGGER update_threads_error_on_delete_mms " +" BEFORE DELETE ON pdu" +" WHEN OLD._id IN (SELECT DISTINCT msg_id" +" FROM pending_msgs" +" WHERE err_type >= 10) " +"BEGIN " +" UPDATE threads SET error = error - 1" +" WHERE _id = OLD.thread_id; " +"END;");// Update the error flag of threads while moving an MM out of Outbox,// which was failed to be sent permanently.db.execSQL("CREATE TRIGGER update_threads_error_on_move_mms " +" BEFORE UPDATE OF msg_box ON pdu " +" WHEN (OLD.msg_box = 4 AND NEW.msg_box != 4) " +" AND (OLD._id IN (SELECT DISTINCT msg_id" +" FROM pending_msgs" +" WHERE err_type >= 10)) " +"BEGIN " +" UPDATE threads SET error = error - 1" +" WHERE _id = OLD.thread_id; " +"END;");// Update the error flag of threads after a text message was// failed to send/receive.db.execSQL("CREATE TRIGGER update_threads_error_on_update_sms " +" AFTER UPDATE OF type ON sms" +" WHEN (OLD.type != 5 AND NEW.type = 5)" +" OR (OLD.type = 5 AND NEW.type != 5) " +"BEGIN " +" UPDATE threads SET error = " +" CASE" +" WHEN NEW.type = 5 THEN error + 1" +" ELSE error - 1" +" END " +" WHERE _id = NEW.thread_id; " +"END;");}
4. 特别为Mms设计的triggers
从中可以得知对于Mms delivery report/read report信息是分别作为一条数据项放在pdu表中的。
// Cleans up parts when a MM is deleted.db.execSQL("CREATE TRIGGER part_cleanup DELETE ON " + MmsProvider.TABLE_PDU + " " +"BEGIN " +" DELETE FROM " + MmsProvider.TABLE_PART +" WHERE " + Part.MSG_ID + "=old._id;" +"END;");// Cleans up address info when a MM is deleted.db.execSQL("CREATE TRIGGER addr_cleanup DELETE ON " + MmsProvider.TABLE_PDU + " " +"BEGIN " +" DELETE FROM " + MmsProvider.TABLE_ADDR +" WHERE " + Addr.MSG_ID + "=old._id;" +"END;");// Delete obsolete delivery-report, read-report while deleting their// associated Send.req.db.execSQL("CREATE TRIGGER cleanup_delivery_and_read_report " +"AFTER DELETE ON " + MmsProvider.TABLE_PDU + " " +"WHEN old." + Mms.MESSAGE_TYPE + "=" + PduHeaders.MESSAGE_TYPE_SEND_REQ + " " +"BEGIN " +" DELETE FROM " + MmsProvider.TABLE_PDU +" WHERE (" + Mms.MESSAGE_TYPE + "=" + PduHeaders.MESSAGE_TYPE_DELIVERY_IND +" OR " + Mms.MESSAGE_TYPE + "=" + PduHeaders.MESSAGE_TYPE_READ_ORIG_IND +")" +" AND " + Mms.MESSAGE_ID + "=old." + Mms.MESSAGE_ID + "; " +"END;");// Update threads table to indicate whether attachments exist when// parts are inserted or deleted.db.execSQL(PART_UPDATE_THREADS_ON_INSERT_TRIGGER);db.execSQL(PART_UPDATE_THREADS_ON_UPDATE_TRIGGER);db.execSQL(PART_UPDATE_THREADS_ON_DELETE_TRIGGER);db.execSQL(PDU_UPDATE_THREADS_ON_UPDATE_TRIGGER);
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