应用程序引擎程序-发生NULL插入错误

Question

我有一个下面的Application Engine程序，正在稍作修改，但现在出现NULL插入错误（无法将值NULL插入表'XXX.dbo.PS_ITM_VNDR_UOM_PR'的列'EFFDT'中。在{{1 }}块中有一个While语句：

SQLExec

需要修改程序，以允许在尚未存在UOM（UNIT_OF_MEASURE）的地方插入新记录，因此我删除对UNIT_OF_MEASURE的引用如下，以便该程序评估为Else条件：

SQLExec("SELECT A.VENDOR_ID FROM PS_ITM_VENDOR A, PS_ITM_VNDR_UOM B WHERE A.SETID = B.SETID AND A.INV_ITEM_ID = B.INV_ITEM_ID AND A.VENDOR_SETID = B.VENDOR_SETID AND A.VENDOR_ID = B.VENDOR_ID AND A.VENDOR_ID = :1 AND A.INV_ITEM_ID = :2 AND A.ITM_ID_VNDR = :3 AND A.ITM_VNDR_PRIORITY = 1 AND B.UNIT_OF_MEASURE = :4 AND B.CONVERSION_RATE = :5", &VendorId, &InvItemId, &ItmIdVndr, &UOM, &ConvRate, &VendorId_check);

但是，当我从上述代码块中删除UNIT_OF_MEASURE SQL和Variable时，我在表ITM_VNDR_UOM_PR的EFFDT列上收到NULL插入错误。似乎在＆SQL CreateSQL中定义的＆UOM变量没有继承到Insert SQL代码中。为什么会发生这种情况？在插入新行时，我该怎么做才能纠正并仍然能够使用＆UOM的原始实例/值？下面是整个程序步骤：

SQLExec("SELECT A.VENDOR_ID FROM PS_ITM_VENDOR A, PS_ITM_VNDR_UOM B WHERE A.SETID = B.SETID AND A.INV_ITEM_ID = B.INV_ITEM_ID AND A.VENDOR_SETID = B.VENDOR_SETID AND A.VENDOR_ID = B.VENDOR_ID AND A.VENDOR_ID = :1 AND A.INV_ITEM_ID = :2 AND A.ITM_ID_VNDR = :3 AND A.ITM_VNDR_PRIORITY = 1   AND B.CONVERSION_RATE = :4", &VendorId, &InvItemId, &ItmIdVndr, &ConvRate, &VendorId_check);