SQL SELECT LIKE (Insensitive casing)

问题

I am trying to execute the sql query:

select * from table where column like '%value%';

But the data is saved as 'Value' ( V is capital ).

When I execute this query i don't get any rows. How do i make the call such that, it looks for 'value' irrespective of the casing of the characters ?

回答1:

use LOWER Function in both (column and search word(s)). Doing it so, you assure that the even if in the query is something like %VaLuE%, it wont matter

select qt.*
from query_table qt
where LOWER(column_name) LIKE LOWER('%vAlUe%');

回答2:

If you want this column be case insensitive :

ALTER TABLE `schema`.`table` 
CHANGE COLUMN `column` `column` TEXT CHARACTER SET 'utf8' COLLATE 'utf8_general_ci';

Thus, you don't have to change your query.

And the MySQL engine will process your query quicker than using lower() function or any other tricks.

And I'm not sure that using lower function will be a good solution for index searching performance.

回答3:

Either use a case-insensitive collation on your table, or force the values to be lower case, e.g.

WHERE lower(column) LIKE lower('%value%');

回答4:

Use the lower() function:

select t.*
from table t
where lower(column) like '%value%';

回答5:

Try using a case insensitive collation

select * from table
where column like '%value%' collate utf8_general_ci

回答6:

If you are using PostgreSQL, a simpler solution is to use insensitive like (ILIKE):

SELECT * FROM table WHERE column ILIKE '%value%'

回答7:

you should use either lower or upper function to ignore the case while you are searching for some field using like.

select * from student where upper(sname) like 'S%';

select * from student where lower(sname) like 'S%';

来源：https://stackoverflow.com/questions/18853452/sql-select-like-insensitive-casing

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mysql

sql

sql-like

case-insensitive