我有如下的查询操作。如果dwb\u acct\u clss\u stg2是stage table，dwb\u acct\u class是target table，如何编写单个合并查询？

INSERT INTO DWB_ACCT_CLSS_STG2
SELECT
STG1.ACCT_CLSS_CD
,STG1.ACCT_CLSS_NME
,STG1.ACCT_CLSS_DSC 
,STG1.PROCESS_NAME
,STG1.EXECUTION_ID
,STG1.FILE_ID
,STG1.FILE_DATE
,STG1.DATA_DATE
,STG1.LOAD_USER
,STG1.LOAD_DATE
,STG1.DW_LAST_UPDATE_TIME
FROM DWB_ACCT_CLSS_STG1 STG1
LEFT OUTER JOIN DWB_ACCT_CLASS TRGT
ON STG1.ACCT_TYP_CD = TRGT.ACCT_TYP_CD
WHERE TRGT.ACCT_TYP_CD IS NULL;

INSERT INTO DWB_ACCT_TYP_STG2
SELECT
STG1.ACCT_TYP_CD
,STG1.ACCT_TYP_DSC
,STG1.PROCESS_NAME
,STG1.EXECUTION_ID
,STG1.FILE_ID
,STG1.FILE_DATE
,STG1.DATA_DATE
,STG1.LOAD_USER
,STG1.LOAD_DATE
,STG1.DW_LAST_UPDATE_TIME
FROM DWB_ACCT_CLASS_STG1 STG1
INNER JOIN DWB_ACCT_CLASS TRGT
ON STG1.ACCT_TYP_CD = TRGT.ACCT_TYP_CD
WHERE (
STG1.ACCT_TYP_DSC <> TRGT.ACCT_TYP_DSC
);

DELETE FROM DWB_ACCT_class WHERE (ACCT_TYP_CD) IN (SELECT ACCT_TYP_CD FROM DWB_ACCT_CLASS_STG2 STG2);

INSERT INTO DWB_ACCT_CLASS SELECT * FROM DWB_ACCT_CLASS_STG2;