table-alias

I've just learned ( yesterday ) to use "exists" instead of "in". BAD select * from table where nameid in ( select nameid from othertable where otherdesc = 'SomeDesc' ) GOOD select * from table t where exists ( select nameid from othertable o where t.nameid = o.nameid and otherdesc = 'SomeDesc' ) And I have some questions about this: 1) The explanation as I understood was: "The reason why this is better is because only the matching values will be returned instead of building a massive list of possible results" . Does that mean that while the first subquery might return 900 results the second

Say I have a select statement that goes.. select * from animals That gives a a query result of all the columns in the table. Now, if the 42nd column of the table animals is is_parent , and I want to return that in my results, just after gender , so I can see it more easily. But I also want all the other columns. select is_parent, * from animals This returns ORA-00936: missing expression . The same statement will work fine in Sybase, and I know that you need to add a table alias to the animals table to get it to work ( select is_parent, a.* from animals ani ), but why must Oracle need a table

I am using a SQL statement with a Temporary relation, and am getting the error ORA-009933: SQL command not properly ended I don't see anything wrong with the statement, so any assistance is greatly appreciated. The statement is: SELECT Temp.name, Temp.AvgSalary FROM (SELECT A.aid, A.aname AS name, AVG(E.salary) AS AvgSalary FROM Aircraft A, Certified C, Employees E) AS Temp; Thanks oracle does not support as for table aliases, only for column aliases and they are optional for that use => delete all as keywords ;) You shouldn't put the AS temp. When putting alias to a table (or subquery) you

I'm curious to know how people are using table aliases. The other developers where I work always use table aliases, and always use the alias of a, b, c, etc. Here's an example: SELECT a.TripNum, b.SegmentNum, b.StopNum, b.ArrivalTime FROM Trip a, Segment b WHERE a.TripNum = b.TripNum I disagree with them, and think table aliases should be use more sparingly. I think they should be used when including the same table twice in a query, or when the table name is very long and using a shorter name in the query will make the query easier to read. I also think the alias should be a descriptive name

I'm trying to execute this query in Oracle SQL Developer: SELECT G.Guest_ID, G.First_Name, G.Last_Name FROM Guest AS G JOIN Stay AS S ON G.Guest_ID = S.Guest_ID WHERE G.City = 'Miami' AND S.Room = '222'; However, I get the following error: ORA-00933: SQL command not properly ended 00933. 00000 - "SQL command not properly ended" *Cause: *Action: Error at Line: 2 Column: 12 I don't see any problem in line 2 and the error is not very descriptive. It appears to be something to do with the as keyword. If I remove it, it works fine. However, I want my queries to be very verbose. Therefore, I must