SSM工程错误，错误提示
### Error querying database. Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for xxxx ### Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for <span style="font-family: Arial, Helvetica, sans-serif;">xxxx</span>] with root cause java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for xxxx
查找后发现为Mapper的命名空间错误