組合2個不相關查詢的輸出

Question

我需要一次執行2個查詢並在一個組合輸出中生成結果。無論是查詢只返回1行

查詢1：

SELECT city, state FROM "Table1" WHERE Id = '123' 

查詢2：

select count(*) as colCount from "Table2" where name = "xyz" 

輸出格式：city, state, colCount

Answer 1

使用子查詢：

SELECT city, state, 
     colCount = (SELECT count(*) 
        FROM Table2 
        WHERE name = "xyz") 
FROM Table1 
WHERE Id = '123' 

子渠ery不能返回多於一行。但如上所述，情況並非如此。你可以使用TOP 1來確保它，但如果它是例外，我寧願有一個例外。

Answer 2

以下查詢會爲你工作：

SELECT city, state, 
     colCount = (SELECT count(*) 
        FROM Table2 
        WHERE name = "xyz") as colCount 
FROM Table1 
WHERE Id = '123'