SQL - Finding minimum value among table fields and joined fields -
This is an interesting and probably good general problem. How do I get the minimum time value associated with ID in a specific table? It is hard to explain without an example, so here's one:
- Field ID in Step A, step 1_date, step2_data
- Field A_ID (AID) in Table B1 I want to find the minimum value between Esteem 1_date, Estes 2_date, Date,
Field A_ID (Funk for AID), Date
in Table B2. B2.date for each ID in B1.date, A2
Any idea anyone?
Unfortunately, at least ()
function returns NULL < / Code> If any of its logic is
NULL
. And, maybe you want to use the left outer join for this purpose, if one of the B tables is not missing A_ID
.
Here's a safe method:
Choose from ID, from mind to mind (Select ID, All Union ID options, Step 2_Date, All of Union Select a_id, date from B1 union, pick date from B2) T-Group by ID;
Comments
Post a Comment