我进行了一个查询，该查询应该向我显示某些日期之间的延迟天数，由于某种原因，它在运行时不显示任何内容。 我有满足条件的数据。
SELECT JOB.JOB_ID, JOB.CUSTOMER, JOB.COUNTRY, QUOTATION.CLASSIFICATION,
QUOTATION.INBOX_DATE, QUOTATION.TECH_EVALUATION_DATE,
QUOTATION.COST_ANALYSIS_DATE, QUOTATION.PRICING_AND_QUOTATION_DATE,
QUOTATION.OUTBOX_DATE, QUOTATION.INBOX_DELAY,
QUOTATION.TECH_EVALUATION_DELAY, QUOTATION.COST_ANALYSIS_DELAY,
QUOTATION.PRICING_AND_QUOTATION_DELAY,
IIf([INBOX_DATE]=Null And [TECH_EVALUATION_DATE]=Null,0,DateDiff("w",
[INBOX_DATE],[TECH_EVALUATION_DATE],2)) AS INBOX_DAYS,
IIf(TECH_EVALUATION_DATE=Null And COST_ANALYSIS_DATE=Null,0,DateDiff("w",
[TECH_EVALUATION_DATE],[COST_ANALYSIS_DATE],2)) AS TECH_EVALUATION_DAYS,
IIf(COST_ANALYSIS_DATE=Null And
PRICING_AND_QUOTATION_DATE=Null,0,DateDiff("w",[COST_ANALYSIS_DATE],
[PRICING_AND_QUOTATION_DATE],2)) AS COSTING_DAYS,
IIf(PRICING_AND_QUOTATION_DATE=Null And OUTBOX_DATE=Null,0,DateDiff("w",
[PRICING_AND_QUOTATION_DATE],[OUTBOX_DATE],2)) AS PRICING_DAYS,
IIf([OUTBOX_DATE]=Null And [ORDER].[ORDER_DATE]=Null,0,DateDiff("w",
[OUTBOX_DATE],[ORDER].[ORDER_DATE],2)) AS OUTBOX_DAYS
FROM (JOB INNER JOIN QUOTATION ON JOB.[JOB_ID] = QUOTATION.[JOB_ID]) INNER
JOIN [ORDER] ON JOB.JOB_ID = ORDER.JOB_ID
WHERE (((QUOTATION.CLASSIFICATION)="Special") AND
((Year([QUOTATION.INBOX_DATE]))=Year(Now())) AND
((Month([QUOTATION.INBOX_DATE]))=Month(Now())-1));