在Mysql數據庫中，多張表之間的數據通常是相互關聯的。這些關聯有助于實現復雜的數據查詢和數據處理，因此需要建立這些表之間的連接。下面將介紹如何在Mysql中建立五個表的連接。

CREATE TABLE `employee` (
`id` int NOT NULL AUTO_INCREMENT,
`name` varchar(50) NOT NULL,
`department_id` int NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `department` (
`id` int NOT NULL AUTO_INCREMENT,
`name` varchar(50) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `task` (
`id` int NOT NULL AUTO_INCREMENT,
`name` varchar(50) NOT NULL,
`employee_id` int NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `attendance` (
`id` int NOT NULL AUTO_INCREMENT,
`employee_id` int NOT NULL,
`punch_time` datetime NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `salary` (
`id` int NOT NULL AUTO_INCREMENT,
`employee_id` int NOT NULL,
`salary` double NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

以上代碼創建了五個表：employee（員工表）、department（部門表）、task（任務表）、attendance（考勤表）、salary（薪資表）。

接下來，我們將通過使用外鍵將這些表連接起來。每個表都有一個主鍵，通過主鍵來建立連接。

ALTER TABLE `employee` ADD CONSTRAINT `employee_department_fk`
FOREIGN KEY (`department_id`) REFERENCES `department` (`id`)
ON DELETE RESTRICT
ON UPDATE CASCADE;
ALTER TABLE `task` ADD CONSTRAINT `task_employee_fk`
FOREIGN KEY (`employee_id`) REFERENCES `employee` (`id`)
ON DELETE RESTRICT
ON UPDATE CASCADE;
ALTER TABLE `attendance` ADD CONSTRAINT `attendance_employee_fk`
FOREIGN KEY (`employee_id`) REFERENCES `employee` (`id`)
ON DELETE CASCADE
ON UPDATE CASCADE;
ALTER TABLE `salary` ADD CONSTRAINT `salary_employee_fk`
FOREIGN KEY (`employee_id`) REFERENCES `employee` (`id`)
ON DELETE CASCADE
ON UPDATE CASCADE;

以上代碼將建立employee表與department表的連接，task表與employee表的連接，attendance表與employee表的連接，以及salary表與employee表的連接。這些連接將會在刪除或更新數據時起到作用。

通過以上操作，五個表之間的連接成功建立，便可以對這些表進行復雜的數據處理和查詢。