相当于 HIVE 查询中的 MERGE

Question

我有以下 SQL 查询：

MERGE INTO member_staging x
USING (SELECT member_id, first_name, last_name, rank FROM members) y
ON (x.member_id  = y.member_id)
WHEN MATCHED THEN
    UPDATE SET x.first_name = y.first_name, 
                        x.last_name = y.last_name, 
                        x.rank = y.rank
    WHERE x.first_name <> y.first_name OR 
           x.last_name <> y.last_name OR 
           x.rank <> y.rank 
WHEN NOT MATCHED THEN
    INSERT(x.member_id, x.first_name, x.last_name, x.rank)  
    VALUES(y.member_id, y.first_name, y.last_name, y.rank);

我想在 Hive 查询中实现它，HIVE 中是否有 MERGE JOIN 的等效项？

Answer 1

手动输入：

• https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DML#LanguageManualDML-Merge

语法示例：

MERGE INTO <target table> AS T USING <source expression/table> AS S
ON <boolean expression1>
WHEN MATCHED [AND <boolean expression2>] THEN UPDATE SET <set clause list>
WHEN MATCHED [AND <boolean expression3>] THEN DELETE
WHEN NOT MATCHED [AND <boolean expression4>] THEN INSERT VALUES<value list>

您的具体案例：

MERGE INTO member_staging AS x
USING (SELECT member_id, first_name, last_name, rank FROM members) y
ON (x.member_id  = y.member_id)
WHEN MATCHED AND (
    x.first_name <> y.first_name OR 
    x.last_name <> y.last_name OR 
    x.rank <> y.rank
)
THEN
    UPDATE SET x.first_name = y.first_name, 
               x.last_name  = y.last_name, 
               x.rank       = y.rank
WHEN NOT MATCHED THEN
    INSERT VALUES (y.member_id, y.first_name, y.last_name, y.rank);