mybatis mapping file mapper
EDITORIAL
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Deletions changed parameters and return values
- parameterType can be omitted
- Interface return value can be returned Integer, Long, Boolean, int, long, boolean, void, mybatis has been good for us encapsulates
<insert id="addRow">
</insert>
public Boolean addRow(Elemployee emp);
Get the value of increment primary key
Premise: a database primary key is auto-incremented
mysql
oracle
mybatis parameters
A single parameter
What single parameter may # {}
Multiple parameters
A plurality of parameters, mybatis encapsulated into a frame parameters will map, the value from the map. key to param1, param2 or @Param ( "emp") custom aliases. value is our parameter values
The difference between the $ and #
resultTupe return value
Returns a collection of
resultType write the elements of the collection type Employee
The return value map
Returns a key-value
resultType = map mybatis we already had a map package is an alias for
the result:
Key column name, value is the value
Back plurality of key-value
Id as the key to
the name of the whole class resultType = Employee of
the results:
key value for the id
value for the value of the object Employe
resultMap return value
the result is a custom set resultMap
resultMap is a very important concept, the next section will focus on it
