Sql-server – Using IF and other conditions in T-SQL (trying to import data from Oracle using SQL Server SSIS)

I am using SQL Server 2012 SSIS package to fetch data from Oracle and insert it into SQL Server 2012.

I am doing it for the first time and every thing is fine i.e. all data from a particular table is being inserted into table in SQL Server.

But I want to place a condition i.e. if some record is new, only then add it in SQL Server. For e.g. there is an ID field in Oracle table which I can check in SQL Server table so if that particular ID is already present in SQL Server table then do not insert it.

I think this IF condition cannot be used in regular SQL and I have to use T-SQL which I have never used so how do I write this simple condition? Suppose following is table structure:

Oracle
Table: OracleTable
Fields: ID, Name

SQL Server
Table: SQLTable
Fields: ID, Name

So it will be something like:

SELECT * FROM OracleTable;
If (Oracle.ID != SQL.ID)
    INSERT INTO SQLTable(rest of the query here)

Or may be there is some option available in SSIS which will allow me to do this without writing query?