问题描述
我只需要一个从 tableB.Field 到 tableA.Field 的唯一结果 我正在使用 sdo 运算符 sdo_nn,这是代码:
UPDATE table1 t1
SET t1.fieldA = (SELECT T2.fieldB,SDO_NN_disTANCE(1) distance
FROM table1 T1,table2 T2
WHERE
(sdo_nn(t1.geometry,t2.geometry,'SDO_NUM_RES=1',1)= 'TRUE')
ORDER BY disT
)
WHERE EXISTS(
SELECT 1
FROM table2 t2
WHERE sdo_nn(t1.geometry,1)='TRUE'
AND(t2.cell_name = 'string1' or t2.cell_name = string2')AND t1.fieldA = NULL
);
在子查询的选择语句中我得到一个错误,因为我只使用了一个字段(t1.fieldA),但是在语句中我使用了运算符 SDO_NN_disTANCE(1) 和 sql 开发人员将此运算符视为另一个字段。这句话的正确写法是什么?我只使用 sql 因为我需要在 vba 中插入这段代码
谢谢!!!
解决方法
显然,你不能(简化)
set t1.fieldA = (t2.fieldB,distance) --> you want to put two values into a single column
因此,从使用分析函数(fieldB
)按row_number
对行“排序”的子查询中单独获取sdo_nn_distance(1) desc
;然后获取第一行的 fieldB
值。
像这样(我希望我把括号设置正确):
UPDATE table1 t1
SET t1.fieldA =
(SELECT x.fieldB --> only fieldB
FROM (SELECT T2.fieldB,--> from your subquery
SDO_NN_DISTANCE (1) distance,ROW_NUMBER ()
OVER (ORDER BY sdo_nn_distance (1) DESC) rn
FROM table1 T1,table2 T2
WHERE (sdo_nn (t1.geometry,t2.geometry,'SDO_NUM_RES=1',1) = 'TRUE')) x
WHERE rn = 1) --> where RN = 1
WHERE EXISTS
(SELECT 1
FROM table2 t2
WHERE sdo_nn (t1.geometry,1) = 'TRUE'
AND ( t2.cell_name = 'string1'
OR t2.cell_name = 'string2')
AND t1.fieldA IS NULL);