调整为内部给予默认 dbType mysql

mybatis-plus-core/src/main/java/com/baomidou/mybatisplus/core/config/GlobalConfig.java

@@ -19,15 +19,15 @@ import java.io.Serializable;
 import java.util.Set;
 import java.util.concurrent.ConcurrentSkipListSet;
 
+import org.apache.ibatis.session.SqlSession;
+import org.apache.ibatis.session.SqlSessionFactory;
+
 import com.baomidou.mybatisplus.annotation.DbType;
 import com.baomidou.mybatisplus.annotation.FieldStrategy;
 import com.baomidou.mybatisplus.annotation.IdType;
+import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
 import com.baomidou.mybatisplus.core.handlers.SqlReservedWordsHandler;
 import com.baomidou.mybatisplus.core.incrementer.IKeyGenerator;
-import org.apache.ibatis.session.SqlSession;
-import org.apache.ibatis.session.SqlSessionFactory;
-
-import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
 import com.baomidou.mybatisplus.core.injector.ISqlInjector;
 import com.baomidou.mybatisplus.core.toolkit.GlobalConfigUtils;
 
@@ -95,11 +95,12 @@ public class GlobalConfig implements Serializable {
     }
 
     @Data
-    public static class DbConfig{
+    public static class DbConfig {
+
         /**
          * 数据库类型
          */
-        private DbType dbType;
+        private DbType dbType = DbType.MYSQL;
         /**
          * 主键类型（默认 ID_WORKER）
          */

mybatis-plus-core/src/main/java/com/baomidou/mybatisplus/core/toolkit/GlobalConfigUtils.java

@@ -82,7 +82,7 @@ public class GlobalConfigUtils {
      */
     public static GlobalConfig defaults() {
         GlobalConfig config = new GlobalConfig();
-        GlobalConfig.DbConfig dbConfig = new GlobalConfig.DbConfig().setDbType(DbType.MYSQL);
+        GlobalConfig.DbConfig dbConfig = new GlobalConfig.DbConfig();
         config.setDbConfig(dbConfig);
         return config;
     }