如何加入两个 table 以多次扩展某行

Question

table 1

Places              Type
All Places          Food
All Places          Dessert
...

table 2

Places              Weather
JH                  Cloudy
Martin              Sunny
Jones               Rainy
Brownsville         Sunny
Nashville           Sunny

如何获取 table 2 列 Places 并将其与 table 1

合并

我希望 table 1 成为（示例：扩展 All Places 使 table 2 中的每个地方都具有 Food 类型：

Places              Type
JH                  Food
Martin              Food
Jones               Food
Brownsville         Food
Nashville           Food
JH                  Dessert
Martin              Dessert
Jones               Dessert
Brownsville         Dessert
Nashville           Dessert
...

我正在使用 MS Sql 服务器 2012。

更新：

table 1

Specialty                                          Topic
Infectious Disease                                 Not Satisfied
Pediatrics                                         Advice / Triage
All Specialties                                    After Hours
All Specialties                                    Age Restrictions
OBGYN                                              Alpha- Feto Protein

table 2

Specialty                                 Version
All Specialties                           All Specialties
OBGYN                                     2.0
Pediatrics                                1.1
Infectious Disease                        0.9

table 1 应该更新为：

Specialty                                 Topic
Infectious Disease                        Not Satisfied
Pediatrics                                Advice / Triage
OBGYN                                     After Hours
Pediatrics                                After Hours
Infectious Disease                        After Hours
OBGYN                                     Age Restrictions
Pediatrics                                Age Restrictions
Infectious Disease                        Age Restrictions
OBGYN                                     Alpha- Feto Protein

Answer 1

可能是 Cartesian product

SELECT b.places,
       a.type
FROM   table1 a
       CROSS JOIN table2 b
WHERE  a.places = 'All Places'

更新：

SELECT b.places,
       a.type
FROM   table1 a
       CROSS JOIN table2 b
WHERE  a.places = 'All Places'
union 
select places,type from 
table1 
where places <> 'All Places'

如何加入两个 table 以多次扩展某行

How to join two table to expand certain row multiple times

sql-server

join