SQL STRCMP函数

STRCMP字符串函数在SQL中比较作为STRCMP函数参数传递的两个字符串。此函数返回0，如果第一个字符串的长度等于第二个字符串的长度。如果第一个字符串的长度大于第二个字符串的长度，则返回1，否则返回-1。

STRCMP字符串函数的语法

语法1： 此语法在SQL表的两列中使用STRCMP函数：

SELECT STRCMP (Column_Name1, column_Name2) AS Alias_Name FROM Table_Name;

在语法中，我们需要定义那些我们想要比较长度的列的名称。

语法3： 此语法使用STRCMP函数与两个字符串：

SELECT STRCMP (String_1, String_2);

STRCMP字符串函数的示例

示例1： 以下SELECT查询比较JAVATPOINT和EXAMPLES字符串的长度：

SELECT STRCMP ('JAVATPOINT', 'EXAMPLES');

输出：

1

示例 2: 以下SELECT查询比较传入STRCMP函数的两个句子的长度：

SELECT STRCMP ('Website is good', 'javatpoint is good');

输出:

-1

示例3: 以下SELECT查询比较了两个城市的长度：

SELECT STRCMP (  'Delhi', 'Noida');

输出：

0

示例4：这个示例使用了带有结构化查询语言中的表的STRCMP函数。

现在，我们创建一个新的SQL表，以帮助理解STRCMP字符串函数。

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)
);  

下面的CREATE语句创建了 Worker_Info 表：

CREATE TABLE Worker_Info
(
Worker_ID INT NOT NULL PRIMARY KEY,  
Worker_First_Name VARCHAR (100),  
Worker_Last_Name VARCHAR (100),  
Worker_Dept_Id INT NOT NULL,
Worker_Address Varchar(120),
Worker_City Varchar (80),
Worker_Salary INT 
);

下面的INSERT查询将行业工人的记录插入到 Worker_Info 表中：

INSERT INTO Worker_Info (Worker_ID, Worker_First_Name, Worker_Last_Name Worker_Dept_Id, Worker_Address, Worker_City, Worker_Salary) VALUES (1001, Arush, Sharma, 4001, Aman Vihar, Delhi, 20000);
INSERT INTO Worker_Info (Worker_ID, Worker_First_Name, Worker_Last_Name Worker_Dept_Id, Worker_Address, Worker_City, Worker_Salary) VALUES (1002, Bulbul, Roy, 4002, Nirman Vihar, Delhi, 38000 );
INSERT INTO Worker_Info (Worker_ID, Worker_First_Name, Worker_Last_Name Worker_Dept_Id, Worker_Address, Worker_City, Worker_Salary) VALUES (1004, Saurabh, Sharma, 4001, Sector 128, Mumbai, 45000);
INSERT INTO Worker_Info (Worker_ID, Worker_First_Name, Worker_Last_Name Worker_Dept_Id, Worker_Address, Worker_City, Worker_Salary) VALUES (1005, Shivani, Singhania, 4001, Vivek Vihar, Kolkata, 42000);
INSERT INTO Worker_Info (Worker_ID, Worker_First_Name, Worker_Last_Name Worker_Dept_Id, Worker_Address, Worker_City, Worker_Salary) VALUES (1006, Avinash, Sharma, 4002, Sarvodya Calony, Delhi, 28000);
INSERT INTO Worker_Info (Worker_ID, Worker_First_Name, Worker_Last_Name Worker_Dept_Id, Worker_Address, Worker_City, Worker_Salary)VALUES (1007, Shyam, Besas, 4003, Krishna Nagar, Lucknow, 35000);

下面的SELECT语句显示了上述 Worker_Info 表中插入的记录：

SELECT * FROM Worker_Info;

以下SELECT查询使用了上述Worker_Info表的Worker_First_Name和Worker_City列的STRCMP函数：

SELECT Worker_First_Name, Worker_City, STRCMP (Worker_First_Name, Worker_City) AS Compare_Firstname_City FROM Worker_Info;

此SQL查询比较了每个工作者的名字和城市。

输出：

下面的SELECT查询在上述Worker_Info表的Worker_first_Name和Worker_Last_Name列中使用STRCMP（）函数：

SELECT Worker_First_Name, Worker_Last_Name, STRCMP(Worker_First_Name, Worker_Last_Name) AS STRCMP_Firstname_Lastname FROM Worker_Info;

这个SQL语句比较每个Worker的名字和姓氏。

输出: