錯誤PostgreSQL中

Question

運行MySQL查詢

我寫的查詢在什麼應該是標準的SQL，並在MySQL測試它們。

現在，當我嘗試在PostgreSQL可以運行在他們我得到的所有類型的錯誤，我真的不明白。 這裏的原始查詢，在MySQL的工作：

CREATE VIEW popularCSsections AS (
    SELECT sect.csid, COUNT(sc.sid) as numStudents 
    FROM courseSection sect, studentCourse sc, department d 
    WHERE sect.csid = sc.csid 
     AND sect.dcode = d.dcode 
     AND dname = "Computer Science" 
    GROUP BY sect.csid 
    HAVING numStudents > 2 
); 

給出了這樣的錯誤：

psql:a2tables:60: ERROR: column "Computer Science" does not exist 
LINE 8: AND department.dname = "Computer Science" 
           ^

能否請你幫我理解錯誤的性質和幫助我解決這些問題？

---

其他問題：

CREATE VIEW popularCSsections AS (
SELECT sect.csid, COUNT(sc.sid) as numStudents 
FROM courseSection sect, studentCourse sc, department d 
WHERE sect.csid = sc.csid 
    AND sect.dcode = d.dcode 
    AND dname = 'Computer Science' 
    GROUP BY sect.csid 
    HAVING numStudents > 2 
); 

錯誤：

psql:a2tables:70: ERROR: column "numstudents" does not exist 
LINE 8: HAVING numStudents > 2 
       ^

Answer 1

需要引用字符串用單引號：

AND dname = 'Computer Science' 

這裏發生的是，雙引號被解釋爲「身份ifier引號「，表示您希望將內容解釋爲數據庫標識符（列或表名稱）。