You can achieve this with the help of CONCAT() along with REPLACE() function. To find the first occurrences you need to use INSTR() function.
The syntax is as follows −
UPDATE yourTableName SET UserPost = CONCAT(REPLACE(LEFT(yourColumnName, INSTR(yourColumnName, 'k')), 'k', 'i'), SUBSTRING(yourColumnName, INSTR(yourColumnName, 'k') + 1));
To understand the above syntax, let us create a table. The query to create a table is as follows −
mysql> create table UserInformation -> ( -> UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> UserName varchar(10), -> UserPost text -> ); Query OK, 0 rows affected (2.05 sec)
Now you can insert some records in the table using insert command. The query is as follows −
mysql> insert into UserInformation(UserName,UserPost) values('Larry','Thks is a MySQL query'); Query OK, 1 row affected (0.16 sec) mysql> insert into UserInformation(UserName,UserPost) values('Mike','Thks is not a java program'); Query OK, 1 row affected (0.31 sec) mysql> insert into UserInformation(UserName,UserPost) values('Sam','Thks is a SQL syntax'); Query OK, 1 row affected (0.18 sec)
Display all records from the table using a select statement. The query is as follows −
mysql> select *from UserInformation;
The following is the output −
+--------+----------+----------------------------+ | UserId | UserName | UserPost | +--------+----------+----------------------------+ | 1 | Larry | Thks is a MySQL query | | 2 | Mike | Thks is not a java program | | 3 | Sam | Thks is a SQL syntax | +--------+----------+----------------------------+ 3 rows in set (0.00 sec)
Here is the query to search/replace but only the first time a value appears in a record. Here, the first occurrence of ‘k’ is replaced with ‘i’ −
mysql> update UserInformation -> set UserPost=CONCAT(REPLACE(LEFT(UserPost, INSTR(UserPost, 'k')), 'k', 'i'), -> SUBSTRING(UserPost, INSTR(UserPost, 'k') + 1)); Query OK, 3 rows affected (0.16 sec) Rows matched: 3 Changed: 3 Warnings: 0
Display all records from the table once again. The query is as follows −
mysql> select *from UserInformation;
The following is the output displaying the first occurrence of ‘k’ replaced with ‘I’ −
+--------+----------+----------------------------+ | UserId | UserName | UserPost | +--------+----------+----------------------------+ | 1 | Larry | This is a MySQL query | | 2 | Mike | This is not a java program | | 3 | Sam | This is a SQL syntax | +--------+----------+----------------------------+ 3 rows in set (0.00 sec)