Here is my first table from which I will read the Distinct Manager column value. It is shown below.
Now see all the records in my Employee Table.
Figure 1: Employee Table
Now select Distinct Manager from this table as in the following:
Figure 2: Select a name
Here is my second table in which I will insert the Manager name:
Figure 3: Insert a name
Now write your SQL statement to achieve our desired functionality:
- INSERT INTO Manager(ManagerName)
- SELECT DISTINCT ManagerName
- FROM Employee
- WHERE ManagerName NOT IN(SELECT ManagerName FROM Manager);
Figure 4: Execute Query
Now select records from the manager table:
Figure 5: Select Record
If you hit this Query again then it will not insert any duplicate records into the Manager records and if a new manager name is to be inserted into the Employee table then it will insert that newly added manager name:
Figure 6: Hit the Query