I have a table with columns CompanyID, EmployeeCode. EmployeeCode is unique and CompanyID can be repeated. So we can keep a list of employees in Google, Apple etc.
I want a way to ensure that the same employee cannot be added if he/she is already in the database. What would be a good way to do this ? I'd prefer not to create additional columns or tables for this.
Create a UNIQUE constraint on the column where you want to prevent duplicates:
CREATE UNIQUE INDEX [IX_YourTableName_EmployeeCode] ON [YourTableName] (EmployeeCode)
CREATE UNIQUE INDEX ... (column1, column2, column3)Try this..
Create table UniqueTable
(
CompanyID int,
EmployeeCode int
)
--Insert dummy data
INSERT INTO UniqueTable(EmployeeCode ,CompanyID ) Values(1,200)
--When are Going to insert duplicate Ecmployeecode '1' then it will not insert data into table
INSERT INTO UniqueTable(EmployeeCode ,CompanyID )
Select 1,200 From UniqueTable t1
Left join UniqueTable t2 on 1=t2.EmployeeCode
WHERE t2.EmployeeCode IS NULL
--We are Going to insert different Ecmployeecode '2' it will insert into table
INSERT INTO UniqueTable(EmployeeCode ,CompanyID )
Select 2,300 From UniqueTable t1
Left join UniqueTable t2 on 2=t2.EmployeeCode
WHERE t2.EmployeeCode IS NULL
Try this
Create PROCEDURE [dbo].[sp_Emp_Insert]
@EmployeeCode nvarchar(50)
As
Begin
if Not Exists (select EmployeeCode from YOUR_TABlE where EmployeeCode =@EmployeeCode )
Begin
Insert QUERY
End
else
Return 0
End
End
insertget the count usingselectquery with where condition depending on result you can allow to insert.STOREPROCEDURE