What is the difference between Mybatis # {}and $,

What is the difference between Mybatis # {}and $,

Dynamic SQL is one of the powerful features of Mybatis and an important reason for its superiority over other ORM frameworks. Before pre-compiling SQL statements, Mybatis dynamically parses the SQL statements and parses them into a BoundSql object. It also processes dynamic SQL statements. In the dynamic SQL parsing phase, # {}and $ {} have different performance:

Select * from user where name =#{ name}

# {} Is resolved as a parameter tag during dynamic parsing. The parsed statement is:

Select * from user where name =?

When we use $:

Select * from user where name =$ {name}

During dynamic parsing, $ {} fills the input parameter into our statement as a String, and then becomes the following statement:

Select * from user where name = "dato"

The SQL statement before pre-compilation does not contain variables, and it is completely constant data. It is equivalent to an SQL statement without variables.

In summary, the replacement phase of the $ {} variable is in the dynamic SQL parsing phase, while the replacement of the # {} variable is in the DBMS.

This is the main difference between # {} and $ {}. In addition, there are the following differences: