我只需要Oracle sdo_nn Update语句中的一个唯一结果， [英] I need only one unique result in Oracle sdo_nn Update sentence ,

问题描述

我只需要一个唯一的结果，从tableB.Field到tableA.Field我正在使用sdo运算符sdo_nn，这是代码:

I need Only one unique result from tableB.Field to tableA.Field I am using sdo operator sdo_nn, this is the code:

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, t2.geometry,'SDO_NUM_RES=1',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，因为我仅使用一个字段(t1.fieldA)，但是在语句中，我使用了运算符 SDO_NN_DISTANCE(1) 和sql developer将这个运算符计为另一个字段.写这句话的正确方法是什么?我只使用sql，因为我需要将此代码插入vba

In the select sentence of the subquery i get an error because i only use one field(t1.fieldA), but in the sentence i use the operator SDO_NN_DISTANCE(1) and the sql developer count this operator like another field. What is the correct way to write this sentence? I only use sql because i need to insert this code in vba

谢谢！

推荐答案

很显然，您不能(简化)

Obviously, you can't (simplified)

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( row_number )进行排序"的子查询中，单独获取 fieldB .按 sdo_nn_distance(1)desc 进行的行；然后获取第一行的 fieldB 值.

Therefore, get fieldB alone from the subquery which uses analytic function (row_number) to "sort" rows by sdo_nn_distance(1) desc; then get the first row's fieldB value.

类似这样的东西(希望我设置正确的括号):

Something like this (I hope I set the parenthesis right):

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,
                              t2.geometry,
                              'SDO_NUM_RES=1',
                              1) = 'TRUE'
                  AND (   t2.cell_name = 'string1'
                       OR t2.cell_name = 'string2')
                  AND t1.fieldA IS NULL);

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