SQL UPPER函数

该字符串函数将Structured Query Language（结构化查询语言）中的所有字符串字符显示为大写。它将小字符或一组小字符转换为大写字母。

我们还可以将UPPER函数与SQL表的字符串字段一起使用。

UPPER字符串函数的语法

语法1： 此语法将UPPER函数与SQL表的列名称一起使用：

SELECT UPPER(Column_Name) AS Alias_Name FROM Table_Name;

在语法中，我们必须指定要在哪个列名上使用UPPER字符串函数。

语法2： 该语法使用UPPER函数和一组小写字符（字符串）：

SELECT UPPER(String);

语法2： 这个语法使用UPPER函数和小写字符：

SELECT UPPER(lower_case_character);

UPPER String函数的示例

示例1：下面的SELECT查询将以下字符串的所有字符转换为大写：

SELECT UPPER(javatpoint is a good website);

输出：

JAVATPOINT IS A GOOD WEBSITE

示例2：以下SELECT查询无法改变以下字符串的字符，因为在SQL中UPPER函数无法改变字符串的符号和整数。

SELECT UPPER(@#$12453@#);

输出：

@#$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);

输出结果：

NEW DELHI IS THE CAPITAL OF INDIA

示例 4：下面的SELECT查询在输出中以大写形式显示字符’s’：

SELECT UPPER( s );

输出：

S

示例5：此示例使用SQL表中的UPPER函数

在此示例中，我们将创建一个新表，其中的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语句创建了 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查询将大学Faculty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 语句显示了上述 Faculty_Info 表中的插入记录：

SELECT * FROM Faculty_Info;