GROUP_CONCAT

GROUP_CONCAT([DISTINCT] expr [,expr ...]
             [ORDER BY {unsigned_integer  col_name  expr}
                 [ASC  DESC] [,col_name ...]]
             [SEPARATOR str_val])

obclient> SELECT * FROM book;     // Table book (book ID, book name, and publisher)
+--------+--------------------------------+-----------------------------+
 bookid  bookname                        publishername                 
+--------+--------------------------------+-----------------------------+
      1  GiT Help                        Alibaba Group     
      2  MySQL Performance Optimization                   Zhejiang University Press          
      3  JAVA Programming Guide                    China Machine Press              
      3  JAVA Programming Guide                    China Machine Press              
      4  Large-Scale Distributed Storage System            China Machine Press              
+--------+--------------------------------+-----------------------------+
5 rows in set (0.00 sec)    

//Search for book name
obclient> SELECT GROUP_CONCAT(bookname) FROM book GROUP BY bookname;
+-----------------------------------+
 GROUP_CONCAT(bookname)            
+-----------------------------------+
 GiT Help                          
 JAVA Programming Guide, JAVA Programming Guide 
 MySQL Performance Optimization                     
 Large-Scale Distributed Storage System              
+-----------------------------------+
4 rows in set (0.00 sec)

//Search for the book name. The book name is unique.
obclient> SELECT GROUP_CONCAT(distinct(bookname)) FROM book GROUP BY bookname;
+----------------------------------+
 GROUP_CONCAT(distinct(bookname)) 
+----------------------------------+
 GIT Help                         
 JAVA Programming Guide                     
 MySQL Performance Optimization                    
 Large-Scale Distributed Storage System              
+----------------------------------+
4 rows in set (0.01 sec)    

//Search for the book name and publisher information, group the information by book name, and display the publisher information in descending order.
obclient> SELECT bookname, GROUP_CONCAT(publishname ORDER BY publishname DESC SEPARATOR ';' ) FROM book GROUP BY bookname;
+--------------------------------+---------------------------------------------------------------------+
 bookname                        GROUP_CONCAT(publishname ORDER BY publishname DESC SEPARATOR ';' ) 
+--------------------------------+---------------------------------------------------------------------+
 GiT Help                        Alibaba Group                                             
 JAVA Programming Guide                    China Machine Press; China Machine Press                                       
 MySQL Performance Optimization                   Zhejiang University Press                                                  
 Large-Scale Distributed Storage System            China Machine Press                                                      
+--------------------------------+---------------------------------------------------------------------+
4 rows in set (0.00 sec)