刻度、数值范围,表示该字段的小数位数
nullable 是否可为空
unsigned 是否无符号
insertable 是否可插入
queryable 是否可查询
systemable 是否系统字段
updatable...,
"nullable": false,
"queryable": false,
"systemable": true,
"unsigned": true,
"updatable...,
"nullable": false,
"queryable": true,
"systemable": true,
"unsigned": false,
"updatable...,
"nullable": true,
"queryable": false,
"systemable": true,
"unsigned": false,
"updatable..."nullable": false,
"queryable": false,
"systemable": true,
"unsigned": false,
"updatable