你不需要一个循环，你可以用一个UPDATE语句来运行它。除此之外，您应该切换到现代的（嗯，它已经存在了20多年）ANSI连接语法。

UPDATE @table_name SET ENTRP_CUST_ID_NUM = ( 
    SELECT mfu_source.Enterprise_Customer_ID 
        FROM {{sourceTableLatest('Aggregation[table]')}} PARTITION ({{getSourcePartitionNameLatest('Aggregation[table]')}}) AGG
            JOIN {{sourceTableLatest('mfu_table')}} PARTITION ({{getSourcePartitionNameLatest('mfu_table')}}) mfu_source ON mfu_source.TA_LINK_ID = AGG.TRD_REF_NUM OR mfu_source.TRANSACTION_ID = AGG.TRD_REF_NUM
    WHERE TRIM(AGG.ENTRP_CUST_ID_NUM) IS NULL 
        AND TRD_REF_NUM = Agg.TRD_REF_NUM)
WHERE EXISTS 
    (SELECT 'x' 
        FROM {{sourceTableLatest('Aggregation[table]')}} PARTITION ({{getSourcePartitionNameLatest('Aggregation[table]')}}) AGG
            JOIN {{sourceTableLatest('mfu_table')}} PARTITION ({{getSourcePartitionNameLatest('mfu_table')}}) mfu_source ON mfu_source.TA_LINK_ID = AGG.TRD_REF_NUM OR mfu_source.TRANSACTION_ID = AGG.TRD_REF_NUM
    WHERE TRIM(AGG.ENTRP_CUST_ID_NUM) IS NULL 
        AND TRD_REF_NUM = Agg.TRD_REF_NUM)

您可以使用单个MERGE语句（而不是循环中的多个语句）：

Declare
  l_status varchar2(10);
Begin
  Insert into @table_name (ENTRP_CUST_ID_NUM, CUST_SROGT_ID, TRD_REF_NUM, CNTRY_CD)
  Select ENTRP_CUST_ID_NUM, CUST_SROGT_ID, TRD_REF_NUM, CNTRY_CD 
  from   {{sourceTableLatest('Aggregation[table]')}} partition ({{getSourcePartitionNameLatest('Aggregation[table]')}});

  MERGE INTO @table_name dst
  USING (
    Select mfu_source.Customer_Surrogate_ID CUST_SROGT_ID,
           Agg.TRD_REF_NUM TRD_REF_NUM,
           mfu_source.Enterprise_Customer_ID ENTRP_CUST_ID_NUM
    from   {{sourceTableLatest('Aggregation[table]')}} partition ({{getSourcePartitionNameLatest('Aggregation[table]')}}) AGG
           INNER JOIN {{sourceTableLatest('mfu_table')}} partition ({{getSourcePartitionNameLatest('mfu_table')}}) mfu_source
           ON    mfu_source.TA_LINK_ID     = AGG.TRD_REF_NUM
              or mfu_source.TRANSACTION_ID = AGG.TRD_REF_NUM
    Where  trim(AGG.ENTRP_CUST_ID_NUM) is null
  ) src
  ON dst.TRD_REF_NUM = src.TRD_REF_NUM
  WHEN MATCHED THEN
    UPDATE
    SET dst.ENTRP_CUST_ID_NUM = src.ENTRP_CUST_ID_NUM;

  Commit;
END;
/