When the MyBatis parameter is list, verifies that the list is empty, MyBatis ${} differs from #{}, MyBatis SQL in

1, when the MyBatis parameter is list, check whether the list is empty

2. The difference between MyBatis ${} and #{}

In short, #{} is a placeholder? can prevent SQL injection, such as the printed statement select * FROM table where id=?

However, ${} is a statement that cannot prevent SQL injection from being printed out of a select * from table where id=2 is a  real parameter.

The simplest difference is that the ${} parse passes through the parameter values without single quotes, #{} parse passes over the parameters with single quotes.

Finally summarize the case that you must use the $ reference parameter, which is the int of the parameter, you must use the $ reference.

3. Mybatis SQL in
Parameter Pass List

1 <SelectID= "Findbyidsmap"Resultmap= "Baseresultmap">  2 Select3  <includerefID= "Base_column_list" />  4 From Jria where ID in5  <foreachItem= "Item"Index= "Index"Collection= "List"Open="("Separator=","Close=")">  6 #{item}7  </foreach>  8 </Select>  

When the MyBatis parameter is list, verifies that the list is empty, MyBatis ${} differs from #{}, MyBatis SQL in