摘要:
表联结分三步: 1.笛卡尔积 (cross join) select * from dbo.Student as S cross join dbo.Address as A 假如dbo.Student有m行,dbo.Address有n行,返回m*n行数据 2.on筛选 (inner join, in 阅读全文
摘要:
参考地址:https://www.tslang.cn/docs/handbook/basic-types.html 1.类的构造函数中的参数使用public修饰符,类默认包含该属性 2.类型转换 方式一:尖括号: var num : any = "30"; var age : number = <n 阅读全文