mapper.xml映射数据库和实体类报错
报错信息：java.lang.AbstractMethodError: Method oracle/jdbc/driver/OracleResultSetImpl.getNString(Ljava/lang/String;)Ljava/lang/String; is abstract,
问题：在mapper.xml代码中 jdbcType 定义的跟数据库中的和实体类中的不一致，
解决方案1：暴力解决，直接去掉mapper.xml中定义的resultMap中的jdbcType ，不指定数据类型
解决方案2：逐个检查 实体类、数据库、resultMap中的数据类型，这三者要保持一致
附：MySQL数据类型、JDBC数据类型、Java数据类型的默认映射关系
| MySQL数据类型 | JDBC类型(getColumnTypeName) | 默认返回的Java类型(getColumnClassName) |
|---|---|---|
BIT(1) (new in MySQL-5.0) |
BIT |
java.lang.Boolean |
BIT( > 1) (new in MySQL-5.0) |
BIT |
byte[] |
TINYINT |
TINYINT |
java.lang.Boolean if the configuration property tinyInt1isBit is set to true (the default) and the storage size is 1, or java.lang.Integer if not. |
BOOL, BOOLEAN |
TINYINT |
See TINYINT, above as these are aliases for TINYINT(1), currently. |
SMALLINT[(M)] [UNSIGNED] |
SMALLINT [UNSIGNED] |
java.lang.Integer (regardless of whether it is UNSIGNED or not) |
MEDIUMINT[(M)] [UNSIGNED] |
MEDIUMINT [UNSIGNED] |
java.lang.Integer (regardless of whether it is UNSIGNED or not) |
INT,INTEGER[(M)] [UNSIGNED] |
INTEGER [UNSIGNED] |
java.lang.Integer, if UNSIGNED java.lang.Long |
BIGINT[(M)] [UNSIGNED] |
BIGINT [UNSIGNED] |
java.lang.Long, if UNSIGNED java.math.BigInteger |
FLOAT[(M,D)] |
FLOAT |
java.lang.Float |
DOUBLE[(M,B)] |
DOUBLE |
java.lang.Double |
DECIMAL[(M[,D])] |
DECIMAL |
java.math.BigDecimal |
DATE |
DATE |
java.sql.Date |
DATETIME |
DATETIME |
java.sql.Timestamp |
TIMESTAMP[(M)] |
TIMESTAMP |
java.sql.Timestamp |
TIME |
TIME |
java.sql.Time |
YEAR[(2|4)] |
YEAR |
If yearIsDateType configuration property is set to false, then the returned object type is java.sql.Short. If set to true (the default), then the returned object is of type java.sql.Datewith the date set to January 1st, at midnight. |
CHAR(M) |
CHAR |
java.lang.String (unless the character set for the column is BINARY, then byte[] is returned. |
VARCHAR(M) [BINARY] |
VARCHAR |
java.lang.String (unless the character set for the column is BINARY, then byte[] is returned. |
BINARY(M) |
BINARY |
byte[] |
VARBINARY(M) |
VARBINARY |
byte[] |
TINYBLOB |
TINYBLOB |
byte[] |
TINYTEXT |
VARCHAR |
java.lang.String |
BLOB |
BLOB |
byte[] |
TEXT |
VARCHAR |
java.lang.String |
MEDIUMBLOB |
MEDIUMBLOB |
byte[] |
MEDIUMTEXT |
VARCHAR |
java.lang.String |
LONGBLOB |
LONGBLOB |
byte[] |
LONGTEXT |
VARCHAR |
java.lang.String |
ENUM('value1','value2',...) |
CHAR |
java.lang.String |
SET('value1','value2',...) |
CHAR |
java.lang.String |
MySQL JDBC允许不同数据类型之间相互转换：转换表如下
| MySQL数据类型 | 可以被转换的Java类型 |
|---|---|
CHAR, VARCHAR, BLOB, TEXT, ENUM, and SET |
java.lang.String, java.io.InputStream, java.io.Reader, java.sql.Blob, java.sql.Clob |
FLOAT, REAL, DOUBLE PRECISION, NUMERIC, DECIMAL, TINYINT, SMALLINT, MEDIUMINT, INTEGER, BIGINT |
java.lang.String, java.lang.Short, java.lang.Integer, java.lang.Long, java.lang.Double, java.math.BigDecimal |
DATE, TIME, DATETIME, TIMESTAMP |
java.lang.String, java.sql.Date, java.sql.Timestamp |
参考MySQL :: MySQL Connector/J 8.0 Developer Guide :: 6.5 Java, JDBC, and MySQL Types