名称映射规则主要负责结构体名称到表名和结构体field到表字段的名称映射。由core.IMapper接口的实现者来管理，xorm内置了三种IMapper实现：core.SnakeMapper ， core.SameMapper和core.GonicMapper。SnakeMapper支持struct为驼峰式命名，表结构为下划线命名之间的转换；SameMapper支持结构体名称和对应的表名称以及结构体field名称与对应的表字段名称相同的命名。
当前SnakeMapper为默认值，如果需要改变时，在engine创建完成后使用
engine.SetMapper(core.SameMapper{})
同时需要注意的是：
engine.SetTableMapper(core.SameMapper{})
engine.SetColumnMapper(core.SnakeMapper{})
When a struct auto mapping to a database's table, the below table describes how they change to each other:
| go type's kind | value method | xorm type |
| implemented Conversion | Conversion.ToDB / Conversion.FromDB | Text |
| int, int8, int16, int32, uint, uint8, uint16, uint32 | Int | |
| int64, uint64 | BigInt | |
| float32 | Float | |
| float64 | Double | |
| complex64, complex128 | json.Marshal / json.UnMarshal | Varchar(64) |
| []uint8 | Blob | |
| array, slice, map except []uint8 | json.Marshal / json.UnMarshal | Text |
| bool | 1 or 0 | Bool |
| string | Varchar(255) | |
| time.Time | DateTime | |
| cascade struct | primary key field value | BigInt |
| struct | json.Marshal / json.UnMarshal | Text |
| Others | Text |