Split the left part of a string by a separator string in MySQL?

You can use substring_index() function from MySQL to split the left part of a string. The syntax is as follows −

SELECT yourColumnName1,.....N,SUBSTRING_INDEX(yourColumnName,’yourSeperatorSymbol’,1) as anyVariableName from yourTableName;

The value 1 indicates that you can get left part of string. To check the above syntax, let us create a table. The query to create a table is as follows −

mysql> create table LeftStringDemo -> ( -> Id int, -> Words varchar(100) -> ); Query OK, 0 rows affected (0.92 sec)

Insert some records in the table using insert command. The query is as follows −

mysql> insert into LeftStringDemo values(1,'MySQL==6789'); Query OK, 1 row affected (0.19 sec) mysql> insert into LeftStringDemo values(2,'Java==Object Oriented'); Query OK, 1 row affected (0.21 sec) mysql> insert into LeftStringDemo values(3,'C Language==Procedural Programming'); Query OK, 1 row affected (0.18 sec) mysql> insert into LeftStringDemo values(4,'PL/SQL==Structured Programming'); Query OK, 1 row affected (0.16 sec)

Display all records from the table using select statement. The query is as follows −

mysql> select *from LeftStringDemo;

The following is the output

+------+------------------------------------+ | Id | Words | +------+------------------------------------+ | 1 | MySQL==6789 | | 2 | Java==Object Oriented | | 3 | C Language==Procedural Programming | | 4 | PL/SQL==Structured Programming | +------+------------------------------------+ 4 rows in set (0.00 sec)

Here is the query that gets the left part of the string column ‘Words’ on the basis of a separator string ‘==’

mysql> select Id, substring_index(Words, '==', 1) as OnlyLefthandsideValue from LeftStringDemo;

The following is the output

+------+-----------------------+ | Id | OnlyLefthandsideValue | +------+-----------------------+ | 1 | MySQL | | 2 | Java | | 3 | C Language | | 4 | PL/SQL | +------+-----------------------+ 4 rows in set (0.00 sec)