What are the functionalities of QueryWrapper in Java?

In Java, QueryWrapper is a query condition constructor provided by MyBatis-Plus to build query conditions. It is primarily used for constructing query conditions and can add conditions using methods like eq, ne, gt, ge, lt, le, in, etc., to create more complex query conditions.

The features of QueryWrapper include:

1. To add search criteria, you can use methods like eq, ne, gt, ge, lt, le, and in.
2. Combine query conditions: multiple query conditions can be combined using keywords such as ‘and’ and ‘or’.
3. Join SQL statements: SQL statements can be joined using methods like where, and, or.
4. Sort search results: You can use the orderBy method to sort the search results.
5. Pagination query: You can conduct pagination query through the use of the page method.
6. Lambda expressions are supported: Lambda expressions can be used to construct query conditions.
7. Entity property query: You can pass an entity object through the entity method and query based on the entity’s properties.

Overall, the QueryWrapper offers a variety of methods to construct query conditions, making it convenient for carrying out flexible search operations.