第一个是max(decode( 两个函数一起应用 的行转列（oracle）

第二个是 case when的 行转列（mysql oracle 都可以 （好像））

两者需要注意的
这里面 的group by 参数 是和函数一样的数据 不能有不一致的数据 比如说 主键id 主键ID是这几行数据都不一样的 加上去之后 就会把原来几条都查出来

SELECT 
max(decode(hs.PAY_TAB_CODE, '235', hs.PAY_TAB_NAME)) payrollTax,max(decode(hs.PAY_TAB_CODE, '231', hs.PAY_TAB_NAME)) taxableWages 
,max(decode(hs.PAY_TAB_CODE, '242', hs.PAY_TAB_NAME)) paidWages,max(decode(hs.PAY_TAB_CODE, '239', hs.PAY_TAB_NAME)) payable 
,max(decode(hs.PAY_TAB_CODE, '235', hs.T00HS027ID)) payrollTaxId,max(decode(hs.PAY_TAB_CODE, '231', hs.T00HS027ID)) taxableWagesId 
,max(decode(hs.PAY_TAB_CODE, '242', hs.T00HS027ID)) paidWagesId,max(decode(hs.PAY_TAB_CODE, '239', hs.T00HS027ID)) payableId 
,hs.EMPID,
					hs."MONTH",
					hs."YEAR",
					hs.CREATE_DATE createDate,
					
					hs.CREATOR,
					hm2.EMPNO AS CREATORNO,
					hs.COMPID,
					HM.EMPNO,
					HM. NAME AS EmpName
FROM T00HS027 hs , T00HM001 hm  , T00HM001 hm2
	
				WHERE
					hs.EMPID = hm.EMPID
				AND hs.T00HM001ID = hm2.EMPID
		
				AND hs."YEAR" = 2023
				AND hs."MONTH" = 2
				AND hs.COMPID = '2eec30c2dcb34a1e97c570d34ff900f4'
AND
( hs.PAY_TAB_CODE = '235' OR hs.PAY_TAB_CODE = '242' OR hs.PAY_TAB_CODE = '231' OR hs.PAY_TAB_CODE = '239' )

GROUP BY
hs.EMPID,
					hs."MONTH",
					hs."YEAR",
					hs.CREATE_DATE ,
					hs.CREATOR,
					hm2.EMPNO ,
					hs.COMPID,
					HM.EMPNO,
					HM.NAME 
ORDER BY hs."YEAR",hs.MONTH

SELECT
	hs.empId,
hs."MONTH",
					hs."YEAR",
					hs.CREATE_DATE createDate,
				hs.CREATOR,
					hm2.EMPNO AS CREATORNO,
				
					hs.COMPID,
					HM.EMPNO,
					HM. NAME AS EmpName,

				
	MAX (
		CASE
		WHEN hs.PAY_TAB_CODE = '235' THEN
			hs.PAY_TAB_NAME
		END
	) payrollTax,
	MAX (
		CASE
		WHEN hs.PAY_TAB_CODE = '231' THEN
			hs.PAY_TAB_NAME
		END
	) taxableWages,
MAX (
		CASE
		WHEN hs.PAY_TAB_CODE = '242' THEN
			hs.PAY_TAB_NAME
		END
	) paidWages,
MAX (
		CASE
		WHEN hs.PAY_TAB_CODE = '239' THEN
			hs.PAY_TAB_NAME
		END
	) payable,
MAX (
		CASE
		WHEN hs.PAY_TAB_CODE = '235' THEN
			hs.T00HS027ID
		END
	) payrollTaxId,
MAX (
		CASE
		WHEN hs.PAY_TAB_CODE = '231' THEN
			hs.T00HS027ID
		END
	) taxableWagesId,

MAX (
		CASE
		WHEN hs.PAY_TAB_CODE = '242' THEN
			hs.T00HS027ID
		END
	) paidWagesId,

MAX (
		CASE
		WHEN hs.PAY_TAB_CODE = '239' THEN
			hs.T00HS027ID
		END
	) payableId
					
				FROM
					T00HS027 hs,
					T00HM001 hm,
					T00HM001 hm2
				WHERE
					hs.EMPID = hm.EMPID
				AND hs.T00HM001ID = hm2.EMPID
		
				AND hs."YEAR" = 2023
				AND hs."MONTH" = 2
				AND hs.COMPID = '2eec30c2dcb34a1e97c570d34ff900f4'
GROUP BY
	hs.empId,hs."YEAR"
,hs."MONTH",

hs.CREATE_DATE ,hs.CREATOR,hm2.EMPNO ,
hs.COMPID,
					HM.EMPNO,
					HM. NAME