在做两个select语句的union all的过程中,爆出了这个问题,这两个语句单独执行都能顺利执行
于是可能问题在系统面对A语句时生成的 int,char字段,B语句生成的int,varchar2字段
那么问题就简单了,将其转化成相同数据类型的数据即可。
create table t_test1(id number, name varchar2(100)); create table t_test2(id number ,name nvarchar2(100)); -------------------- select t.* from T_TEST1 t; select t.* from T_TEST2 t; -------------------- insert into t_test1 values(1,'nameFromTest1'); insert into t_test2 values(2,'nameFromTest2'); --------------------union all查询 select id, name from t_test1 union all select id, name from t_test2;
然可能工作中比较复杂,比如name字段是由若干内容拼成的,这样系统就会自动判断这个字段该属于什么类型
解决办法如下
---------------------解决办法1 to_char to_nchar select id, name from t_test1 union all select id, to_char(name) from t_test2; ----------------- to_nchar cast translate...using 将varchar2转为nvarchar2 ---------------------------------to_nchar select id, to_nchar(name) from t_test1 union all select id, name from t_test2; ----------------------------------cast select id, cast(name as nvarchar2(100)) from t_test1 union all select id, name from t_test2; ----------------------------------translate...using 2 nchar_cs select id, translate(name using nchar_cs) from t_test1 union all select id, name from t_test2; ----------------------------------translate...using 2 char_cs select id, name from t_test1 union all select id, translate(name using char_cs) from t_test2;