PL/SQL :: Compare Two Tables And Delete The Common Rows From Table 1

I want to compare two tables , and delete the common rows from the first table

Here is what i have done :

Create table test1(Test1C1 Number,
Test1C2 varchar2(50));

Create table test2(Test2C1 Number,
Test2C2 varchar2(50));

Insert into test1 values(1,'testdata1');
Insert into test1 values(2,'testdata2');
Insert into test1 values(3,'testdata3');
[code].......

it deletes all the records from Table test1. What should I modify here ? or should I write a different query ?

The desired contents in table test1 will be

2 testdata2
4 testdata4
6 testdata6
8 testdata8
10 testdata10