Mayatis Abnormal result Maps collection already contains value ...

This exception, used MyBatis is definitely seen, in addition to Online said, a mapper.xml file ID duplicate, there are many errors will lead to this exception, the recent work encountered many new causes of the exception, collected as follows for your reference:

Duplicate ID in 1,xml file, Modify ID

2,resulttype and Resultmap attributes use confusion, which is not used when using Resulttype resulttype

3, namespace error, what do you mean? it is best to try to use the full package name + class name, this includes many cases, sometimes the property value of one more space is not, ' xxx.avo ' and ' Xxx.avo ' is not the same

4, check the XML file corresponding to the Mapper.java interface, ensure one by one corresponding and unique

5. Continuous Update collection after discovery

Mayatis Abnormal result Maps collection already contains value ...