SQL UPPER 函数

一、SQL UPPER 函数 语法

SQL UPPER 函数 以大写形式显示结构化查询语言中的所有字符串字符。它将小字符或一组小字符转换为大写字母。

我们还可以对 SQL 表的字符串字段使用 UPPER 函数。

语法1：此语法将 UPPER 函数与 SQL 表的列名一起使用：

SELECT UPPER(Column_Name) AS Alias_Name FROM Table_Name;  

在语法中，我们必须指定要在其上使用 UPPER 字符串函数的列名。

语法2：此语法使用 UPPER 函数和一组小写字符（字符串）：

SELECT UPPER(String);  

语法3：此语法使用带有单个小写字符的 UPPER 函数：

SELECT UPPER(lower_case_character);  

二、SQL UPPER 函数 示例

示例 1：以下 SELECT 查询将以下字符串的所有字符转换为大写：

SELECT UPPER(yiidian is a good website);  

结果为：

YIIDIAN IS A GOOD WEBSITE

示例 2：以下 SELECT 查询无法更改以下字符串的字符，因为 UPPER 函数无法更改 SQL 中字符串的符号和整数。

SELECT UPPER(@#$12453@#);  

结果为：

@#$12453@#

示例 3：以下 SELECT 查询将小写字母转换为大写字母：

SELECT UPPER(  New Delhi IS the Capital OF India);  

结果为：

NEW DELHI IS THE CAPITAL OF INDIA

示例 4：以下 SELECT 查询在输出中以大写形式显示字符“s”：

SELECT UPPER( s );  

结果为：

S

示例 5：此示例对 SQL 表使用 UPPER 函数

在此示例中，我们将创建一个新表，其字符串列将包含小写字符。

在 SQL 数据库中创建新表的语法如下：

CREATE TABLE table_name  
(  
1st_Column Data Type (character_size of 1st Column),    
2nd_Column Data Type (character_size of the 2nd column ),    
3rd_Column Data Type (character_size of the 3rd column),    
...    
  
Nth_Column Data Type (character_size of the Nth column)  
);    

以下 CREATE 语句创建Faculty_Info表：

CREATE TABLE Faculty_Info  
(  
Faculty_ID INT NOT NULL PRIMARY KEY,    
Faculty_First_Name VARCHAR (100),    
Faculty_Last_Name VARCHAR (100),    
Faculty_Dept_Id INT NOT NULL,  
Faculty_Address Varchar(120),  
Faculty_City Varchar (80),  
Faculty_Salary INT   
);  

下面的 INSERT 语句将大学 Faculties 的记录插入到Faculty_Info表中：

INSERT INTO Faculty_Info (Faculty_ID, Faculty_First_Name, Faculty_Last_Name Faculty_Dept_Id, Faculty_Address, Faculty_City, Faculty_Salary) VALUES (1001, arush, sharma, 4001, aman vihar, delhi, 20000);  
INSERT INTO Faculty_Info (Faculty_ID, Faculty_First_Name, Faculty_Last_Name Faculty_Dept_Id, Faculty_Address, Faculty_City, Faculty_Salary) VALUES (1002, bulbul, roy, 4002, nirman vihar, delhi, 38000 );  
INSERT INTO Faculty_Info (Faculty_ID, Faculty_First_Name, Faculty_Last_Name Faculty_Dept_Id, Faculty_Address, Faculty_City, Faculty_Salary) VALUES (1004, saurabh, sharma, 4001, sector 128, mumbai, 45000);  
INSERT INTO Faculty_Info (Faculty_ID, Faculty_First_Name, Faculty_Last_Name Faculty_Dept_Id, Faculty_Address, Faculty_City, Faculty_Salary) VALUES (1005, shivani, singhania, 4001, vivek vihar, kolkata, 42000);  
INSERT INTO Faculty_Info (Faculty_ID, Faculty_First_Name, Faculty_Last_Name Faculty_Dept_Id, Faculty_Address, Faculty_City, Faculty_Salary) VALUES (1006, avinash, sharma, 4002, sarvodya calony, delhi, 28000);  
INSERT INTO Faculty_Info (Faculty_ID, Faculty_First_Name, Faculty_Last_Name Faculty_Dept_Id, Faculty_Address, Faculty_City, Faculty_Salary)VALUES (1007, shyam, besas, 4003, krishna nagar, lucknow, 35000);  

以下 SELECT 语句显示上述Faculty_Info表的插入记录：

SELECT * FROM Faculty_Info;  

输出结果为：

Faculty_Id	Faculty_First_Name	Faculty_Last_Name	Faculty_Dept_Id	Faculty_Address	Faculty_City	Faculty_Salary
1001	arush	sharma	4001	aman vihar	delhi	20000
1002	bulbul	roy	4002	nirman vihar	delhi	38000
1004	saurabh	roy	4001	sector 128	mumbai	45000
1005	shivani	singhania	4001	vivek vihar kolkata 42000
1006	avinash	sharma	4002	sarvodya calony	delhi	28000
1007	shyam	besas	4003	krishna nagar	lucknow	35000

以下 SELECT 查询将 UPPER 函数与上述 Faculty_Info 表的 Faculty_Last_Name 列一起使用：

SELECT Faculty_Last_Name, UPPER(Faculty_Last_Name) AS UPPER_LastName FROM Faculty_Info;  

此 SQL 语句将上表中每个学院的姓氏转换为大写。

Faculty_Last_Name	UPPER_LastName
sharma	SHARMA
sroy	ROY
sroy	ROY
ssinghania	SINGHANIA
ssharma	SHARMA
sbesas	BESAS

以下 SELECT 查询将 UPPER 函数与上面 Faculty_Info 表中的 Faculty_Id 大于 1002 的那些学院的 Faculty_First_Name、Faculty_City 和 Faculty_Address 列一起使用：

SELECT Faculty_Id, UPPER(Faculty_First_Name), UPPER(Faculty_Address), UPPER(Faculty_City) FROM Faculty_Info WHERE Faculty_Id >1002; 

输出借给我为：

Faculty_Id	UPPER(Faculty_First_Name)	UPPER(Faculty_Address)	UPPER(Faculty_City)
1004	SAURABH	SECTOR 128	MUMBAI
1005	SHIVANI	VIVEK VIHAR	KOLKATA
1006	AVINASH	SARVODYA CALONY	DELHI
1007	SHYAM	KRISHNA NAGAR	LUCKNOW