'SQL 'like' statement in mongodb [duplicate]

MongoDB supports RegularExpressions.

Two ways we can implement regular expression using java API for mongodb:

Expression 1:I need to search start with that string in document field

String strpattern ="your regular expression";Pattern p = Pattern.compile(strpattern);BasicDBObject obj = new BasicDBObject() obj.put("key",p);

Example : (consider I want to search wherever name start with 'a')

String strpattern ="^a";Pattern p = Pattern.compile(strpattern);BasicDBObject obj = new BasicDBObject() obj.put("name",p);

Expression 2:

I need to search multiple words in one field , you can use as follows

String pattern = "\\b(one|how many)\\b";BasicDBObject obj = new BasicDBObject();//if you want to check case sensitiveobj.put("message", Pattern.compile(pattern,Pattern.CASE_INSENSITIVE));

Although you can use regular expressions, you won't get good performance on full text search because a contains query such as /text/ cannot use an index.

A begins-with query such as /^text/ can, however, use an index.

If you are considering full text search on any large scale please consider MongoDB's Multi Key Search feature.

Update

As of MongoDB v3.2 you can also use a text index.