Consequences of missing return types in MyBatis configuration file xxxx.xml A query was run and no Result Maps were found

An exception occurred while using MyBatis:

Like a mistake.

Error querying database. Cause:org.apache.ibatis.executor.executorexception:a query was run and no Result Maps were found for the Mapped statemen T

(Omitted in the following section)

Online says Oracle does not allow null values to be inserted.

But I did not do the insert operation, just made a query.

Then look at MyBatis's configuration file, missing an entry: Resulttype property value

The original configuration is: <select id= "COUNTSITEINV" parametertype= "Map" >

Modified configuration <select id= "COUNTSITEINV" resulttype= "Camelcasekeymap" parametertype= " Map" >

No matter what query in MyBatis, you must return the value of Resulttype or RESULTMAP, otherwise you will get an error.

Consequences of missing return types in MyBatis configuration file xxxx.xml A query was run and no Result Maps were found