MyBatis use of foreach tags in dynamic sql

The foreach tag is primarily used to build in conditions, and he can iterate over the collection in SQL. As follows:

<delete id= "Deletebatch" >

Delete from the user where ID in

<foreach collection= "Array" item= "id" index= "index" open= "(" close= ")" separator= "," >

#{id}

</foreach>

</delete>

If we say that the parameter is----int[] ids = {1,2,3,4,5}----then the following SQL is printed:

Delete form user where ID in (1,2,3,4,5)

Interpretation:

The value of the Collection:collection property is three list, array, map three, respectively, the corresponding parameter type is: List, array, map collection, I passed the argument is an array, so the value is array

Item: Represents an alias for each element during an iteration

Index: Represents the position of each iteration to (subscript) during the iteration

Open: Prefix

　　　　Close: Suffix

Separator: delimiter that represents what separates each element in the iteration

We can usually use it for bulk deletions, additions, and so on.

MyBatis use of foreach tags in dynamic sql