SELECT t1.id, t1.[requestId] AS t1_requestId, t1.[gf] AS '供方', t1.[htmc] AS '合同名称', t1.[htbh] AS '合同编号', t1.[sjbh] AS '编号', t1.[qdrq] AS '签订日期', t1.[qsrq] AS '起始日期', t1.[jzrq] AS '截止日期', t1.[zje] AS '总金额', t1.[zds] AS '总吨数', t1.[rksj] AS '入库时间', t1.[chpt] AS '撮合平台', t1.[qsfs] AS '签署方式', t1.[gfjc] AS '供方简称', t1.[cclx] AS '持仓类型', CAST ( STUFF( ( SELECT ',' + CONVERT ( VARCHAR, CASE WHEN ISNUMERIC( REPLACE( t2.hsdj, ',', '' ) ) = 1 THEN CAST ( REPLACE( t2.hsdj, ',', '' ) AS FLOAT ) END ) FROM formtable_main_43_dt1 t2 WHERE t1.id = t2.mainid FOR XML PATH ( '' ) ), 1, 1, '' ) AS FLOAT ) AS '采购单价' FROM formtable_main_43 t1 INNER JOIN formtable_main_43_dt1 t2 ON t1.id = t2.mainid GROUP BY t1.id, t1.[requestId], t1.[gf], t1.[htmc], t1.[htbh], t1.[sjbh], t1.[qdrq], t1.[qsrq], t1.[jzrq], t1.[zje], t1.[zds], t1.[rksj], t1.[chpt], t1.[qsfs], t1.[gfjc], t1.[cclx], '采购单价';提示每个 GROUP BY 表达式必须至少包含一个不是外部引用的列

根据你提供的 SQL 语句和错误提示，应该是 `GROUP BY` 子句中的问题。在 `GROUP BY` 子句中，只能引用 `SELECT` 列表中的列或者是聚合函数，而不能直接引用字符串常量。你需要将 `'采购单价'` 替换为 `t2.hsdj`，即：

SELECT t1.id, t1.[requestId] AS t1_requestId, t1.[gf] AS '供方', t1.[htmc] AS '合同名称', t1.[htbh] AS '合同编号', t1.[sjbh] AS '编号', t1.[qdrq] AS '签订日期', t1.[qsrq] AS '起始日期', t1.[jzrq] AS '截止日期', t1.[zje] AS '总金额', t1.[zds] AS '总吨数', t1.[rksj] AS '入库时间', t1.[chpt] AS '撮合平台', t1.[qsfs] AS '签署方式', t1.[gfjc] AS '供方简称', t1.[cclx] AS '持仓类型', CAST ( STUFF( ( SELECT ',' + CONVERT ( VARCHAR, CASE WHEN ISNUMERIC( REPLACE( t2.hsdj, ',', '' ) ) = 1 THEN CAST ( REPLACE( t2.hsdj, ',', '' ) AS FLOAT ) END ) FROM formtable_main_43_dt1 t2 WHERE t1.id = t2.mainid FOR XML PATH ( '' ) ), 1, 1, '' ) AS FLOAT ) AS '采购单价' FROM formtable_main_43 t1 INNER JOIN formtable_main_43_dt1 t2 ON t1.id = t2.mainid GROUP BY t1.id, t1.[requestId], t1.[gf], t1.[htmc], t1.[htbh], t1.[sjbh], t1.[qdrq], t1.[qsrq], t1.[jzrq], t1.[zje], t1.[zds], t1.[rksj], t1.[chpt], t1.[qsfs], t1.[gfjc], t1.[cclx], t2.hsdj;

这样就可以正确地对查询结果进行分组。