mapper.xml映射數據庫和實體類報錯
報錯信息：java.lang.AbstractMethodError: Method oracle/jdbc/driver/OracleResultSetImpl.getNString(Ljava/lang/String;)Ljava/lang/String; is abstract,
問題：在mapper.xml代碼中 jdbcType 定義的跟數據庫中的和實體類中的不一致，
解決方案1：暴力解決，直接去掉mapper.xml中定義的resultMap中的jdbcType ，不指定數據類型
解決方案2：逐個檢查 實體類、數據庫、resultMap中的數據類型，這三者要保持一致
附：MySQL數據類型、JDBC數據類型、Java數據類型的默認映射關系
| MySQL數據類型 | JDBC類型(getColumnTypeName) | 默認返回的Java類型(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允許不同數據類型之間相互轉換：轉換表如下
| MySQL數據類型 | 可以被轉換的Java類型 |
|---|---|
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 |
參考MySQL :: MySQL Connector/J 8.0 Developer Guide :: 6.5 Java, JDBC, and MySQL Types