是SQL服務器中可用的查找函數

Question

我正在嘗試執行以下任務。我有兩個表格，包含以下數據？

表1：

objectid name   LOCATION Project Manager 

4584  Client    NULL  Indicator 

4591  Ericsson   NULL  Indicator 

4604  NEW201    Text  NULL 

表2：

projectobjectid  name  value 

4584    Indicator Red 

4591    Indicator Green 

4604    Text   Sf001-bb1-5 

4604    Text   Sf001-bb1-4 

4604    Text   Sf001-bb1-3 

4604    Text   Sf001-bb1-2 

結果如下：從表

objectid name      LOCATION  Project Manager 

4584  Client      NULL    Red 

4591  Ericsson     NULL    Green 

4604   NEW201     Sf001-bb1-5   NULL 

4604   NEW201     Sf001-bb1-4   NULL 

4604   NEW201     Sf001-bb1-3   NULL 

4604   NEW201     Sf001-bb1-2   NULL 

更新表1 2

Answer 1

您可以有兩個這樣做left join s，每列一個要替換：

SELECT t1.objectid, t1.name, l1.value, l2.value 
FROM  table1 t1 
LEFT JOIN table2 l1 ON t1.objectid = l1.projectobjectid AND 
         t1.location = l1.name 
LEFT JOIN table2 l2 ON t1.objectid = l2.projectobjectid AND 
         t1.projectmanager = l2.name 

SQL Fiddle Demo

Answer 2

你去那裏（只有一個左連接）：

SELECT t1.objectid, t1.name, 
CASE t1.location WHEN t2.name THEN t2.value END as Location, 
CASE t1.projectmanager WHEN t2.name THEN t2.value END as ProjectManager 
FROM table1 t1 
LEFT JOIN table2 t2 ON t2.projectobjectid=t1.objectid 

SQL Fiddle Demo