mybatis - Java中类型与数据库mysql、oracle等的对应关系

╰+攻爆jí腚メ 2022-01-30 01:57 285阅读 0赞

在使用mybatis时，会在maper.xml文件中写对应mapper接口类的sql语句，里面会有涉及到Java中类型与数据库mysql、oracle等的对应关系，事实上在mybatis包中有一个名为JdbcType的枚举类，下面记录一下这个枚举类的详情，这样方便开发，感兴趣的可以了解一下。

pom

<dependency>
        <groupId>tk.mybatis</groupId>
        <artifactId>mapper-spring-boot-starter</artifactId>
        <version>2.1.5</version>
    </dependency>

/**
     *    Copyright 2009-2018 the original author or authors.
     *
     *    Licensed under the Apache License, Version 2.0 (the "License");
     *    you may not use this file except in compliance with the License.
     *    You may obtain a copy of the License at
     *
     *       http://www.apache.org/licenses/LICENSE-2.0
     *
     *    Unless required by applicable law or agreed to in writing, software
     *    distributed under the License is distributed on an "AS IS" BASIS,
     *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     *    See the License for the specific language governing permissions and
     *    limitations under the License.
     */
    package org.apache.ibatis.type;
    
    import java.sql.Types;
    import java.util.HashMap;
    import java.util.Map;
    
    /**
     * @author Clinton Begin
     */
    public enum JdbcType {
      /*
       * This is added to enable basic support for the
       * ARRAY data type - but a custom type handler is still required
       */
      ARRAY(Types.ARRAY),
      BIT(Types.BIT),
      TINYINT(Types.TINYINT),
      SMALLINT(Types.SMALLINT),
      INTEGER(Types.INTEGER),
      BIGINT(Types.BIGINT),
      FLOAT(Types.FLOAT),
      REAL(Types.REAL),
      DOUBLE(Types.DOUBLE),
      NUMERIC(Types.NUMERIC),
      DECIMAL(Types.DECIMAL),
      CHAR(Types.CHAR),
      VARCHAR(Types.VARCHAR),
      LONGVARCHAR(Types.LONGVARCHAR),
      DATE(Types.DATE),
      TIME(Types.TIME),
      TIMESTAMP(Types.TIMESTAMP),
      BINARY(Types.BINARY),
      VARBINARY(Types.VARBINARY),
      LONGVARBINARY(Types.LONGVARBINARY),
      NULL(Types.NULL),
      OTHER(Types.OTHER),
      BLOB(Types.BLOB),
      CLOB(Types.CLOB),
      BOOLEAN(Types.BOOLEAN),
      CURSOR(-10), // Oracle
      UNDEFINED(Integer.MIN_VALUE + 1000),
      NVARCHAR(Types.NVARCHAR), // JDK6
      NCHAR(Types.NCHAR), // JDK6
      NCLOB(Types.NCLOB), // JDK6
      STRUCT(Types.STRUCT),
      JAVA_OBJECT(Types.JAVA_OBJECT),
      DISTINCT(Types.DISTINCT),
      REF(Types.REF),
      DATALINK(Types.DATALINK),
      ROWID(Types.ROWID), // JDK6
      LONGNVARCHAR(Types.LONGNVARCHAR), // JDK6
      SQLXML(Types.SQLXML), // JDK6
      DATETIMEOFFSET(-155), // SQL Server 2008
      TIME_WITH_TIMEZONE(Types.TIME_WITH_TIMEZONE), // JDBC 4.2 JDK8
      TIMESTAMP_WITH_TIMEZONE(Types.TIMESTAMP_WITH_TIMEZONE); // JDBC 4.2 JDK8
    
      public final int TYPE_CODE;
      private static Map<Integer,JdbcType> codeLookup = new HashMap<>();
    
      static {
        for (JdbcType type : JdbcType.values()) {
          codeLookup.put(type.TYPE_CODE, type);
        }
      }
    
      JdbcType(int code) {
        this.TYPE_CODE = code;
      }
    
      public static JdbcType forCode(int code)  {
        return codeLookup.get(code);
      }
    
    }

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