Menu
What kind of sql tricks you use to enter data into two tables with a circular reference in between.
Employees
EmployeeID <PK>
DepartmentID <FK> NOT NULL
Departments
DepartmentID <PK>
EmployeeID <FK> NOT NULL
The employee belongs to a department, a department has to have a manager (department head).
Do I have to disable constraints for the insert to happen?
314
In the world of relational databases circular references are schema structures where foreign keys relating the tables create a loop. Circular references cause special types of issues when trying to synchronize two relational database where the foreign keys are enforced.
Circular Dependency : Here when we try to delete a record from TABLE A, it throws an error message as Column P & Column R of TABLE B are depending on Column Q of TABLE A. When we try to delete a record from TABLE B, it again throws an error message as Column P of TABLE A is depending on Column P of TABLE B.
Circular Reference means that your formula is trying to calculate the origin cell. Typically, this is considered an error. However, there are times where this error can actually be useful and you might to want to create a circular reference on purpose.
If there are circular references ("loops") in a data structure, the tables are associated in such a way that there is more than one path of associations between two fields. This type of data structure should be avoided as much as possible, since it might lead to ambiguities in the interpretation of data.
I assume your Departments.EmployeeID is a department head. What I'd do is make that column nullable; then you can create the department first, then the employee.
85
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
