Cannot create a table in mysql error(150) - mysql

Question

I want to create 3 tables called curenttasks, originaltasks and previoustasks. I make one table and copied to other two. But one table cannot create while other 2 are created successfully.
The three table are:
DROP TABLE IF EXISTS `CurrentTasks`;
/*!40101 SET #saved_cs_client = ##character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `CurrentTasks` (
`taskID` mediumint(9) NOT NULL AUTO_INCREMENT,
`taskName` varchar(255) NOT NULL,
`isActive` boolean DEFAULT TRUE,
`startDate` datetime NOT NULL,
`endDate` datetime NOT NULL,
`completeDate` datetime DEFAULT NULL,
`complexityID` smallint(6) NOT NULL,
`managerID` mediumint(9) NOT NULL,
`projectID` mediumint(9) NOT NULL,
`requirementName` varchar(255) NOT NULL,
`xPos` smallint(6) DEFAULT NULL,
`yPos` smallint(6) DEFAULT NULL,
`description` text NOT NULL,
`stageName` enum('Definition','Design','Development','Testing','Evaluation') NOT NULL DEFAULT 'Definition',
PRIMARY KEY (`taskID`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
/*!40101 SET character_set_client = #saved_cs_client */;
--
-- Dumping data for table `CurrentTasks`
--
LOCK TABLES `PreviousTasks` WRITE;
/*!40000 ALTER TABLE `PreviousTasks` DISABLE KEYS */;
/*!40000 ALTER TABLE `PreviousTasks` ENABLE KEYS */;
UNLOCK TABLES;
--
-- Table structure for table `PreviousTasks`
--
DROP TABLE IF EXISTS `PreviousTasks`;
/*!40101 SET #saved_cs_client = ##character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `PreviousTasks` (
`taskID` mediumint(9) NOT NULL AUTO_INCREMENT,
`taskName` varchar(255) NOT NULL,
`isActive` boolean DEFAULT TRUE,
`startDate` datetime NOT NULL,
`endDate` datetime NOT NULL,
`completeDate` datetime DEFAULT NULL,
`complexityID` smallint(6) NOT NULL,
`managerID` mediumint(9) NOT NULL,
`projectID` mediumint(9) NOT NULL,
`requirementName` varchar(255) NOT NULL,
`xPos` smallint(6) DEFAULT NULL,
`yPos` smallint(6) DEFAULT NULL,
`description` text NOT NULL,
`stageName` enum('Definition','Design','Development','Testing','Evaluation') NOT NULL DEFAULT 'Definition',
PRIMARY KEY (`taskID`),
UNIQUE KEY `uniquePreviousTasks` (`requirementName`,`projectID`,`taskName`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
/*!40101 SET character_set_client = #saved_cs_client */;
--
-- Dumping data for table `PreviousTasks`
--
LOCK TABLES `PreviousTasks` WRITE;
/*!40000 ALTER TABLE `PreviousTasks` DISABLE KEYS */;
/*!40000 ALTER TABLE `PreviousTasks` ENABLE KEYS */;
UNLOCK TABLES;
--
-- Table structure for table `OriginalTasks`
--
DROP TABLE IF EXISTS `OriginalTasks`;
/*!40101 SET #saved_cs_client = ##character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `OriginalTasks` (
`taskID` mediumint(9) NOT NULL AUTO_INCREMENT,
`taskName` varchar(255) NOT NULL,
`isActive` boolean DEFAULT TRUE,
`startDate` datetime NOT NULL,
`endDate` datetime NOT NULL,
`completeDate` datetime DEFAULT NULL,
`complexityID` smallint(6) NOT NULL,
`managerID` mediumint(9) NOT NULL,
`projectID` mediumint(9) NOT NULL,
`requirementName` varchar(255) NOT NULL,
`xPos` smallint(6) DEFAULT NULL,
`yPos` smallint(6) DEFAULT NULL,
`description` text NOT NULL,
`stageName` enum('Definition','Design','Development','Testing','Evaluation') NOT NULL DEFAULT 'Definition',
PRIMARY KEY (`taskID`),
UNIQUE KEY `uniqueOriginalTasks` (`requirementName`,`projectID`,`taskName`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
/*!40101 SET character_set_client = #saved_cs_client */;
--
-- Dumping data for table `OriginalTasks`
--
LOCK TABLES `OriginalTasks` WRITE;
/*!40000 ALTER TABLE `OriginalTasks` DISABLE KEYS */;
/*!40000 ALTER TABLE `OriginalTasks` ENABLE KEYS */;
UNLOCK TABLES;
The currenttasks cannot cteate, the error is:
ERROR 1005 (HY000): Can't create table 'rem.currenttasks' (errno: 150)
I just very confused because I delete currenttasks and copied previoustasks to it, replace every previous with current, but it still cannot work.

Answer 1

You forgot to delete lines between 28-31. PreviousTasks table is not created yet, but those lines tries to alter table. Also same thing exist at lines 64-67.