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From: Tyrone B. <tyr...@ho...> - 2007-03-21 02:01:34
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>From: "Robert Manning" <rob...@gm...> >To: "Tyrone Baseck" <tyr...@ho...> >CC: squ...@li... >Subject: Re: [Squirrel-sql-users] SQL 101 >Date: Tue, 20 Mar 2007 17:40:42 -0400 > >On 3/20/07, Tyrone Baseck <tyr...@ho...> wrote: >>I will get help from the DBA on that query listed earlier. The one listed >>below works. Now, what is it doing: >> >>select * from MGD_REQ_HOLDG m inner join AUTH_REQ_ITEM_HDR a on >>m.REQ_ITEM_HDR_ID = a.REQ_ITEM_HDR_ID >>where a.auth_req_id >> >>Do I need to change the MGD_REQ_HOLDG in the first line to look at another >>table? > >You are saying join tables MGD_REQ_HOLDG and AUTH_REQ_ITEM_HDR by >matching records where the field REQ_ITEM_HDR_ID in both tables is >equal. If you need columns from other tables, then you would add them >to your join. The where clause : > >where a.auth_req_id > >is incomplete. You should give a value for auth_req_id like : > >where a.auth_req_id = 42 > >or not include a where clause at all (which could be quite a large >number, depending on the data) > >> >>What is the lower case "m" and "a" for? > >Table aliases are more convenient than using the entire table name. > >> >>Why do you need to add a "a" to a.REQ_ITEM_HDR_ID instead of doing it >>without the "a"? > >Both tables apparently have a column called REQ_ITEM_HDR_ID, so the >database doesn't know which one you are referring to. The table >aliases "m" and "a" tell it which one you mean. > > >Rob Oh!! So the a.REQ_ITEM_HDR_ID can be inputted as the following: AUTH_REQ_ITEM_HDR.REQ_ITEM_HDR_ID No answer needed on that comment. _________________________________________________________________ Exercise your brain! Try Flexicon. http://games.msn.com/en/flexicon/default.htm?icid=flexicon_hmemailtaglinemarch07 |
