Cannot Add Foreign Key Constraint - I Checked almost everything - mysql

Question

okay, so im having a weird issue with this foreign key constraint.
The data type is Int(11) and all tables and databases are using utf8_general_ci but I'm still getting an issue! the only table that inherited the Medicine_ID is the First Aid table.
Here's my schema:
tbl_Medicine
+--------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------------+-------------+------+-----+---------+-------+
| Medicine_ID | int(11) | NO | PRI | NULL | |
| Brand_Name | varchar(45) | YES | | NULL | |
| Generic_Name | varchar(45) | YES | | NULL | |
| Countable | int(11) | YES | | NULL | |
+--------------+-------------+------+-----+---------+-------+
tbl_batch
+---------------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+---------------+---------+------+-----+---------+-------+
| Batch_ID | int(11) | NO | PRI | NULL | |
| Purchase_Date | date | YES | | NULL | |
+---------------+---------+------+-----+---------+-------+
tbl_Stock
+-----------------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------------+---------+------+-----+---------+-------+
| Stock_ID | int(11) | NO | PRI | NULL | |
| Medicine_ID | int(11) | NO | PRI | NULL | |
| Batch_ID | int(11) | NO | PRI | NULL | |
| Expiration_Date | date | YES | | NULL | |
| Quantity | int(45) | YES | | NULL | |
| Unit_Price | int(11) | YES | | NULL | |
+-----------------+---------+------+-----+---------+-------+
tbl_inventory
+--------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------------+-------------+------+-----+---------+-------+
| Inventory_ID | int(11) | NO | PRI | NULL | |
| Building | varchar(45) | NO | PRI | NULL | |
| Stock_ID | int(11) | NO | PRI | NULL | |
| Medicine_ID | int(11) | NO | PRI | NULL | |
| Quantity | varchar(45) | YES | | NULL | |
+--------------+-------------+------+-----+---------+-------+
tbl_Activity
+--------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------------+-------------+------+-----+---------+-------+
| Activity_ID | varchar(10) | NO | PRI | NULL | |
| Purpose | varchar(50) | YES | | NULL | |
| Organization | varchar(50) | YES | | NULL | |
| Reciever | varchar(50) | YES | | NULL | |
| Recieve_Date | date | YES | | NULL | |
| Act_Date | date | YES | | NULL | |
| Validator | varchar(10) | YES | | NULL | |
+--------------+-------------+------+-----+---------+-------+
Heres the creation query:
CREATE TABLE IF NOT EXISTS `csb_inventory`.`tbl_batch` (
`Batch_ID` INT(11) NOT NULL COMMENT '',
`Purchase_Date` DATE NULL DEFAULT NULL COMMENT '',
PRIMARY KEY (`Batch_ID`) COMMENT '')
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8;
CREATE TABLE IF NOT EXISTS `csb_inventory`.`tbl_medicine` (
`Medicine_ID` INT(11) NOT NULL COMMENT '',
`Brand_Name` VARCHAR(45) NULL DEFAULT NULL COMMENT '',
`Generic_Name` VARCHAR(45) NULL DEFAULT NULL COMMENT '',
`Countable` INT(11) NULL DEFAULT NULL COMMENT '',
PRIMARY KEY (`Medicine_ID`) COMMENT '')
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8;
CREATE TABLE IF NOT EXISTS `csb_inventory`.`tbl_stock` (
`Stock_ID` INT(11) NOT NULL COMMENT '',
`Medicine_ID` INT(11) NOT NULL COMMENT '',
`Batch_ID` INT(11) NOT NULL COMMENT '',
`Expiration_Date` DATE NULL DEFAULT NULL COMMENT '',
`Quantity` INT(45) NULL DEFAULT NULL COMMENT '',
`Unit_Price` INT(11) NULL DEFAULT NULL COMMENT '',
PRIMARY KEY (`Stock_ID`, `Medicine_ID`, `Batch_ID`) COMMENT '',
INDEX `fk_tbl_Stock_tbl_Medicine_idx` (`Medicine_ID` ASC) COMMENT '',
INDEX `fk_tbl_Stock_tbl_Batch1_idx` (`Batch_ID` ASC) COMMENT '',
CONSTRAINT `batch`
FOREIGN KEY (`Batch_ID`)
REFERENCES `csb_inventory`.`tbl_batch` (`Batch_ID`)
ON DELETE NO ACTION
ON UPDATE NO ACTION,
CONSTRAINT `medicine`
FOREIGN KEY (`Medicine_ID`)
REFERENCES `csb_inventory`.`tbl_medicine` (`Medicine_ID`)
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8;
CREATE TABLE IF NOT EXISTS `csb_inventory`.`tbl_inventory` (
`Inventory_ID` INT(11) NOT NULL COMMENT '',
`Building` VARCHAR(45) NOT NULL COMMENT '',
`Stock_ID` INT(11) NOT NULL COMMENT '',
`Medicine_ID` INT(11) NOT NULL COMMENT '',
`Quantity` VARCHAR(45) NULL DEFAULT NULL COMMENT '',
PRIMARY KEY (`Inventory_ID`, `Building`, `Stock_ID`, `Medicine_ID`) COMMENT '',
INDEX `fk_tbl_Inventory_tbl_Building1_idx` (`Building` ASC) COMMENT '',
INDEX `fk_tbl_Inventory_tbl_Stock1_idx` (`Stock_ID` ASC, `Medicine_ID` ASC) COMMENT '',
CONSTRAINT `building`
FOREIGN KEY (`Building`)
REFERENCES `csb_patient`.`tbl_building` (`Building`),
CONSTRAINT `stockitem`
FOREIGN KEY (`Stock_ID` , `Medicine_ID`)
REFERENCES `csb_inventory`.`tbl_stock` (`Stock_ID` , `Medicine_ID`)
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8;
CREATE TABLE IF NOT EXISTS `csb_inventory`.`tbl_firstaid` (
`FirstAid_ID` VARCHAR(10) NOT NULL COMMENT '',
`Activity_ID` VARCHAR(10) NOT NULL COMMENT '',
`Quantity` SMALLINT(6) NOT NULL COMMENT '',
`Inventory_ID` INT(11) NOT NULL COMMENT '',
`Medicine_ID` INT(11) NOT NULL COMMENT '',
PRIMARY KEY (`FirstAid_ID`, `Activity_ID`, `Inventory_ID`, `Medicine_ID`) COMMENT '',
INDEX `activity_id` (`Activity_ID` ASC) COMMENT '',
INDEX `fk_tbl_firstaid_tbl_inventory1_idx` (`Inventory_ID` ASC, `Medicine_ID` ASC) COMMENT '',
CONSTRAINT `activity_id`
FOREIGN KEY (`Activity_ID`)
REFERENCES `csb_inventory`.`tbl_activity` (`Activity_ID`)
ON DELETE NO ACTION
ON UPDATE NO ACTION,
CONSTRAINT `fk_tbl_firstaid_tbl_inventory1`
FOREIGN KEY (`Inventory_ID` , `Medicine_ID`)
REFERENCES `csb_inventory`.`tbl_inventory` (`Inventory_ID` , `Medicine_ID`)
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8;
I have read alot of threads regarding the same issue and tested them out.
I made sure that im using the same table_type, collation, and data_type. I even checked all other tables that are related that might have been causing the issue but no good. I was able to successfully add foreign keys to firstAid but only the Medicine_ID is the one failing.
help? xD

Answer 1

Make sure that you have tbl_building on before create tbl_inventory.