使用设置参数在JPA查询中插入特殊字符

Question

Is there a way in JPA 2.0 to set parameter of a query with special characters? I mean, if I do: query.setParameter(field, "%" + value.toString() + "%"); , it takes % as special (wildcard) character? It seems to me it's not true in this case, beacuse my search doesn't work with truncated words... Can You help me??

Answer 1

If you are using

LIKE :feild 

for

query.setParameter(field, "%" + value.toString() + "%");

Then value remains free from the '%' sign. You can try to use % in your query and send value from setParameter() method.

You can also try CreteriaBuilderInterface of JPA. http://www.objectdb.com/java/jpa/query/jpql/string .

Answer 2

you have to escape the query. try to use "\\\\%" instead

Answer 3

what ever you pass in as a query parameter that will pass on to query and back to database. So to the choice of escape character of the query parameter will depend on database. Like in mysql it is "\\'" for "'" and "\\%" for "%" so if I want to send "john's 10% commission" as query parameter to mysql, i will try query.setParameter(field, "john\\\\'s 10\\\\% commission") ; in your case query.setParameter(field, "\\\\%" + value.toString() + "\\\\%"); should work. But check the documentation of the database to find out escape character for special cases.