MERGE 与 MERGE INTO 之间有什么区别？

Question

MERGE 与 MERGE INTO 之间有什么区别？
每个的用例是什么？

令人惊讶的是，我找不到任何询问这种差异的现有问题。

MERGE的文档也没有解释这一点，并且它仅在似乎与该差异（如果有）无关的情况下使用一次。

Answer 1

MERGE的语法图：

[ WITH <common_table_expression> [,...n] ]  
MERGE
    [ TOP ( expression ) [ PERCENT ] ]
    [ INTO ] <target_table> [ WITH ( <merge_hint> ) ] [ [ AS ] table_alias ]  
    USING <table_source> [ [ AS ] table_alias ]
    ON <merge_search_condition>  
    [ WHEN MATCHED [ AND <clause_search_condition> ]  
        THEN <merge_matched> ] [ ...n ]  
    [ WHEN NOT MATCHED [ BY TARGET ] [ AND <clause_search_condition> ]  
        THEN <merge_not_matched> ]  
    [ WHEN NOT MATCHED BY SOURCE [ AND <clause_search_condition> ]  
        THEN <merge_matched> ] [ ...n ]  
    [ <output_clause> ]  
    [ OPTION ( <query_hint> [ ,...n ] ) ]
;  

表示这[ INTO ] 是可选的。就像INSERT一样，它存在与否没有任何区别。