Question

我有一个查询，其中第一列显示名称长度，第二列显示名称或礼貌我已经完成了这些但我的第三列遇到了问题。它应该使用子字符串并显示名字的首字母和姓氏初始，任何人都可以告诉我如何将此功能添加到我已经拥有的内容中吗？

这是查询

SELECT 'Your full name is ' + CAST(LEN(FirstName) + LEN(LastName) AS VARCHAR(12)) + ' character(s).' AS [Length of Employee Name], 
       CASE TitleOfCourtesy WHEN 'Mr.' THEN 'Mister '
                            WHEN 'mrs. ' THEN 'Miss'
                            WHEN 'Ms.' THEN 'Miss '
                            WHEN 'Dr.' THEN 'Doctor '
                            ELSE '' END + TitleOfCourtesy + LastName AS title
FROM dbo.Employees

Answer 1

（因为您使用了LEN我假设您使用的是SQL Server）

你的意思是这样的吗？

substring(FirstName,1,1) + substring(LastName,1,1)

一般情况是这样的：

substring(expression, startPosition, lenght)

Answer 2

我会使用LEFT（）而不是substring。

DECLARE @Employees TABLE (FirstName VARCHAR(25),LastName VARCHAR(25), TitleOfCourtesy VARCHAR(5))
INSERT INTO @Employees
VALUES  ('Bob','Brown','Mr.'),
        ('Olivia','Taylor','M rs.'),
        ('Grace','Stevens','Ms.'),
        ('Theodor','Seuss','Dr.');


SELECT  'Your full name is ' + CAST(LEN(FirstName) + LEN(LastName) AS VARCHAR(12)) + ' character(s).' AS [Length of Employee Name], 
        CASE Replace(TitleOfCourtesy, ' ','') --Gets rid of any white space
                WHEN 'Mr.'      THEN 'Mister'
                WHEN 'mrs.'     THEN 'Miss'
                WHEN 'Ms.'      THEN 'Miss'
                WHEN 'Dr.'      THEN 'Doctor'
                ELSE ''
        END + ' ' + LastName AS title,
        CONCAT(LEFT(FirstName,1),'.',LEFT(LastName,1),'.') AS Initials
FROM @Employees

结果：

Length of Employee Name                      title                            Initials
-------------------------------------------- -------------------------------- --------
Your full name is 8 character(s).            Mister Brown                     B.B.
Your full name is 12 character(s).           Miss Taylor                      O.T.
Your full name is 12 character(s).           Miss Stevens                     G.S.
Your full name is 12 character(s).           Doctor Seuss                     T.S.

有人可以给我一些关于如何使用子串函数的技巧

2 个答案: