SQL Server data set intersection, union, and difference set operations

For the relationship between them, refer to the following figure to show the relevant test examples:
 
The test examples are as follows:
Copy codeThe Code is as follows:
Use tempdb
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If (object_id ('t1') is not null) drop table t1
If (object_id ('t2') is not null) drop table t2
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Create table t1 (a int)
Insert into t1 select 1 union select 2 union select 3
Create table t2 (a int)
Insert into t2 select 3 union select 4 union select 5
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Select * from t1 union select * from t2
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/* Calculate the table Union
1
2
3
4
5 */
Select * from t1 union all select * from t2
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/* The Union of tables does not filter duplicates.
1
2
3
3
4
5 */
Select * from t1 distinct T select * from t2
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/* Calculate the difference set between t1 and t2
1
2 */
Select * from t1 intersect select * from t2
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/* Calculate the intersection of t1 to t2
3 */