SELECT t1.id, t1.[kh] AS '客户', t1.[lrsj] AS '录入时间', t1.[htbh] AS '合同编号', t1.[rq] AS '签订日期', t1.[htqsrq] AS '起始日期', t1.[htjzrq] AS '截止日期', t1.[zjey] AS '总金额', t1.[hjzld] AS '总吨数', t1.[lrsj] AS '创建时间', t1.[chpt] AS '撮合平台', CAST ( t1.[htwj] AS VARCHAR ( MAX ) ) AS '合同文件', STUFF( ( SELECT ',' + CONVERT ( VARCHAR, CASE WHEN ISNUMERIC( REPLACE( t2.ppcs, ',', '' ) ) = 1 THEN CAST ( REPLACE( t2.ppcs, ',', '' ) AS FLOAT ) END ) FROM uf_xsht_dt1 t2 WHERE t1.id = t2.mainid FOR XML PATH ( '' ) ), 1, 1, '' ) AS '品牌', STUFF( ( SELECT ' ' + CONVERT ( VARCHAR, CASE WHEN ISNUMERIC( REPLACE( t2.hsdjyd, ' ', '' ) ) = 1 THEN CAST ( REPLACE( t2.hsdjyd, ' ', '' ) AS FLOAT ) END ) FROM uf_xsht_dt1 t2 WHERE t1.id = t2.mainid FOR XML PATH ( '' ) ), 1, 1, '' ) AS '销售单价', (SELECT SUM ( sjfk ) from uf_xshksj2 WHERE cght=t1.id ) AS '实际已收', (SELECT SUM ( hkje ) from uf_xshksj2 WHERE cght=t1.id ) AS '已收货款', ( SELECT SUM( sjfk ) FROM uf_xshksj2 WHERE kxlx = 0 AND cght = t1.id ) AS '订金' FROM uf_xsht t1 INNER JOIN uf_xsht_dt1 t2 ON t1.id = t2.mainid LEFT JOIN uf_xshksj2 t3 ON t1.id = t3.cght GROUP BY t1.id, t1.[kh], t1.[lrsj], t1.[htbh], t1.[rq], t1.[htqsrq], t1.[htjzrq], t1.[zjey], t1.[hjzld], t1.[chpt], CAST ( t1.[htwj] AS VARCHAR ( MAX ) )；中按ID查询计算收款比例‘已收比例’，当订金与已收货款的和小于总金额时，比例公式为已收货款除以总金额；否则为订金与已收货款求和再除以总金额

你可以使用 CASE 表达式来计算收款比例 '已收比例'，根据订金与已收货款的和是否小于总金额来选择不同的计算方式。以下是相应的修改后的查询语句：

SELECT
    t1.id,
    t1.[kh] AS '客户',
    t1.[lrsj] AS '录入时间',
    t1.[htbh] AS '合同编号',
    t1.[rq] AS '签订日期',
    t1.[htqsrq] AS '起始日期',
    t1.[htjzrq] AS '截止日期',
    t1.[zjey] AS '总金额',
    t1.[hjzld] AS '总吨数',
    t1.[lrsj] AS '创建时间',
    t1.[chpt] AS '撮合平台',
    CAST ( t1.[htwj] AS VARCHAR ( MAX ) ) AS '合同文件',
    STUFF(
        (
        SELECT
            ',' + CONVERT (
                VARCHAR,
            CASE
                WHEN ISNUMERIC( REPLACE( t2.ppcs, ',', '' ) ) = 1 THEN
                    CAST ( REPLACE( t2.ppcs, ',', '' ) AS FLOAT ) 
            END 
            ) 
        FROM uf_xsht_dt1 t2 
        WHERE t1.id = t2.mainid FOR XML PATH ( '' ) 
        ),
        1,
        1,
        '' 
    ) AS '品牌',
    STUFF(
        (
        SELECT
            ' ' + CONVERT (
                VARCHAR,
            CASE
                WHEN ISNUMERIC( REPLACE( t2.hsdjyd, ' ', '' ) ) = 1 THEN
                    CAST ( REPLACE( t2.hsdjyd, ' ', '' ) AS FLOAT ) 
            END 
            ) 
        FROM uf_xsht_dt1 t2 
        WHERE t1.id = t2.mainid FOR XML PATH ( '' ) 
        ),
        1,
        1,
        '' 
    ) AS '销售单价',
    (SELECT SUM(sjfk) FROM uf_xshksj2 WHERE cght = t1.id) AS '实际已收',
    (SELECT SUM(hkje) FROM uf_xshksj2 WHERE cght = t1.id) AS '已收货款',
    (SELECT SUM(sjfk) FROM uf_xshksj2 WHERE kxlx = 0 AND cght = t1.id) AS '订金',
    CASE
        WHEN ((SELECT SUM(ISNULL(hkje, 0)) FROM uf_xshksj2 WHERE cght = t1.id) + (SELECT SUM(ISNULL(sjfk, 0)) FROM uf_xshksj2 WHERE kxlx = 0 AND cght = t1.id)) < t1.[zjey] THEN
            (SELECT SUM(ISNULL(hkje, 0)) FROM uf_xshksj2 WHERE cght = t1.id) / t1.[zjey]
        ELSE
            ((SELECT SUM(ISNULL(hkje, 0)) FROM uf_xshksj2 WHERE cght = t1.id) + (SELECT SUM(ISNULL(sjfk, 0)) FROM uf_xshksj2 WHERE kxlx = 0 AND cght = t1.id)) / t1.[zjey]
    END AS '已收比例'
FROM
    uf_xsht t1
    INNER JOIN uf_xsht_dt1 t2 ON t1.id = t2.mainid
    LEFT JOIN uf_xshksj2 t3 ON t1.id = t3.cght 
GROUP BY
    t1.id,
    t1.[kh],
    t1.[lrsj],
    t1.[htbh],
    t1.[rq],
    t1.[htqsrq],
    t1.[htjzrq],
    t1.[zjey],
    t1.[hjzld],
    t1.[chpt],
    CAST ( t1.[htwj] AS VARCHAR ( MAX ) );

在上述查询中，我添加了一个 CASE 表达式来计算 '已收比例'。该表达式首先检查订金与已收货款的和是否小于总金额，如果是，则计算已收货款与总金额的比例；否则，计算订金与已收货款的和与总金额的比例。请根据你的实际需求和数据结构进行适当的调整。