Informix - where子句与merge合并

Question

我正在使用Informix Dynamic Server Version 12.10.FC9W1X2。

我需要使用来自不同表的字段更新表。我试图使用

MERGE INTO 

声明，但我无法使用WHERE CLAUSE过滤掉正在更新的表中的信息，因为它导致语法错误。我也尝试将AND添加到WHEN MATCHED并且它无法正常工作。

有没有办法做到这一点？

这是我到目前为止的发言，

MERGE INTO table1 as t1
USING table2 as t2
   ON t1.some_no = t2.some  
WHEN MATCHED   
    THEN 
UPDATE SET t1.some_other_no = t2.some_other_no, is_processed = 'Y', resolution = 'AAA'

Answer 1

table1上的其他过滤器可以放在ON子句中。例如：

create table t1(col1 int, col2 int, col3 int);

insert into t1 values(1,1,1);
insert into t1 values(1,2,0);
insert into t1 values(1,3,0);
insert into t1 values(2,1,0);
insert into t1 values(3,1,1);

create table t2 (col1 int, col2 int);

insert into t2 values(1,5);
insert into t2 values(2,5);
insert into t2 values(3,5);


merge into t1
using t2
on
    t1.col1 = t2.col1
AND t1.col3 = 1
when matched then
    update set t1.col2 = t2.col2;

The above results in the following output when selecting from the t1 table

       col1        col2        col3

          1           5           1
          1           2           0
          1           3           0
          2           1           0
          3           5           1