I don’t think there are rules for this case and you cannot depend on a particular outcome. If you’re after a specific row, say the latest one, you can use apply, like: UPDATE a SET a.Value = b.Value FROM tableA AS a CROSS APPLY ( select top 1 * from tableB as b where b.id … Read more
You could try the INTERVAL DAY TO SECOND data type but it won’t save you any disk space … it is very suitable for this purpose though. create table t1 (time_of_day interval day (0) to second(0)); insert into t1 values (TO_DSINTERVAL(‘0 23:59:59’)); select date ‘2009-05-13’+time_of_day from t1; 11 bytes though.
Brute force approach: Send it the “.dump” command to create a text representation of the data. Read that data in into the second database. Not sure you can use that. If you need a fine grained update (sending a copy of each upto the other copy), have a look at sqlite3_update_hook But how do you … Read more
max(end_dt) keep (dense_rank first order by end_dt desc nulls first) upd: SQL Fiddle Oracle 11g R2 Schema Setup: CREATE TABLE t (val int, s date, e date) ; INSERT ALL INTO t (val, s, e) VALUES (1, sysdate-3, sysdate-2) INTO t (val, s, e) VALUES (1, sysdate-2, sysdate-1) INTO t (val, s, e) VALUES (1, … Read more
SQL Server does not cache the query results, but it caches the data pages it reads in memory. The data from these pages is then used to produce the query result. You can easily see if the data was read from memory or from disk by setting SET STATISTICS IO ON Which returns the following … Read more
MySQL allows comments on tables and rows. PostgreSQL does as well. From other answers, Oracle and MSSQL have comments too. For me, a combination of UML diagram for a quick refresher on field names, types, and constraints, and an external document (TeX, but could be any format) with extended description of everything database-related – special … Read more
You can check out this blog post. It had solved my problem. http://dotnetguts.blogspot.com/2010/06/restore-failed-for-server-restore.html Select @@Version It had given me following output Microsoft SQL Server 2005 – 9.00.4053.00 (Intel X86) May 26 2009 14:24:20 Copyright (c) 1988-2005 Microsoft Corporation Express Edition on Windows NT 6.0 (Build 6002: Service Pack 2) You will need to re-install to … Read more
You don’t say what version of SQL Server. If SQL Server 2008 you can use MERGE NB: It is usual to use Merge for an Upsert which is what I originally thought the question was asking but it is valid without the WHEN MATCHED clause and just with a WHEN NOT MATCHED clause so does … Read more
In SQL the AND operator takes “precedence” over OR operator. PostgreSQL adheres to the spec here. You can the exact precedence in PostgreSQL in the docs Lexical Structure: Operator Precedence. So in your case, the result will be the same. However, it’s much easier, and cleaner to simply use the parentheses.
It sounds like you might need to create and query linked database servers in SQL Server At the moment you’ve created a query that’s going between different databases using a 3 part name mydatabase.dbo.mytable but you need to go up a level and use a 4 part name myserver.mydatabase.dbo.mytable, see this post on four part … Read more