从合并视图中选择不起作用的组合视图吗? [英] Select out of a combined view with concatenation not working?

问题描述

我尝试使用+在一个列中创建具有两个值的视图，并且该视图已成功创建，但是当我尝试从中选择所有视图时，会出现以下错误:

I tried creating a view with two values in one column using +, and the view was created successfully, but when I try selecting all from it it gives me this error:

select *
        *
ERROR at line 1: 
ORA-01722: invalid number 

我尝试研究此运算符和串联运算符，但令我沮丧的是没有找到任何帮助.这是我用来创建视图的代码，也用于选择.

I tried researching this and the concatenation operator but to my dismay have found no help. Here is the code I used to create the view, and the select also.

CREATE VIEW CombinedNameEmployeePhoneView AS
SELECT (EMPLOYEE.LastName + ' ' + EMPLOYEE.FirstName)
AS EmployeeName, EMPLOYEE.Phone as EmployeePhone
from EMPLOYEE;

select * 
from CombinedNameEmployeePhoneView;

推荐答案

The concatenation operator in Oracle is the double pipe, ||. The + is used for adding numbers together, hence the error.

该视图已成功创建，因为Oracle在创建数据时不会评估数据；只是确保它可以编译.

The view was created successfully because Oracle doesn't evaluate the data when creating it; merely ensures that it compiles.

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