First look at an exception ### Cause: java. SQL. SQLException: ORA-00911: invalid characters; bad SQL grammar []; nested exception is java. SQL. SQLException: ORA-00911: Invalid character: java. SQL. SQLException: ORA-00911: invalid characters I believe you also saw this is invalid character Error Problem source when doing experiments using mysql mapper xml file SQL statement is: <insert id = "saveUser" parameterType = "UserEntity"> insert into C_USER (ID, LOGIN_NAME, PASSWORD, EMAIL) values (# {id}, # {loginName }, # {password}, # {email}); </insert> NO If the problem is changed to oracle, the above error is reported. If you check the error carefully, no error is found. You can also tell which character is invalid, in fact, this is not very serious. If you look at it carefully, you will find the semicolon before the error ........ Remove the semicolon next to the SQL statement. No problem. 1. You should read exception one by one word in the future. 2 oracle SQL does not add points. The author has a bowl of three meals.