Bridge table

An example of a Bridge table would be relationship table between student_master and courses_master. A Student may participate in multiple courses and obviously in a course there will be multiple students. In this scenario to maintain relationships between student_master and courses_master we need another table which may be called Student_courses. This table will have all relationships between Students and Courses.A bridge table is a table that only contains the keys between the two tables in a many-to-many relationship. These tables typically consist of mostly key fields the primary keys of the two tables needing the many to many relationships. Sometimes there are more data elements but often there are only two columns both foreign keys.

A table which maintained to define the relationship between two different tables is known as bridge tables. For example say there are two tables one table with employee information (an employee table) and other with deparment details. Now a bridge table coming to picture to maintain the relationship between an employee with his/her department. which contains informations like which employee belongs to which department. Here is a example to understand More precisely ,this solution will help when one employee is working for different departments at the same point of time.

Employee table--------------------

EMP_CD EMP_name DOJ
1001 MR.X 12-06-2006
1002 Ms.Y 24-11-2004
1003 MS.K 25-02-2004

Department table -----------------------

DEPT_CD DEPT_NAME SECTOR_CD MANAGER_NM
IT_DEV S/W Developer SDV MR.XL
MNGNT HR Management HRD MS.DS


EMP_DEPT (Bridge Table)---------------------------------
EMP_CD DEPT_CD
1001 MNGNT
1002 IT_DEV
1003 IT_DEV