Late answer… You can use CAST or CONVERT thus CAST(foo AS CHAR(100)) CONVERT(foo, CHAR(100)) Supported types (5.5) are: BINARY[(N)] CHAR[(N)] DATE DATETIME DECIMAL[(M[,D])] SIGNED [INTEGER] TIME UNSIGNED [INTEGER] You can not cast to varchar directly. There is an open MySQL bug from 2008 which no-one seems to care about and is damn annoying
[Expanding on dvv’s answer] You can move to an existing table as follows. For unmatched schema, you should specify columns. WITH moved_rows AS ( DELETE FROM <original_table> a USING <other_table> b WHERE <condition> RETURNING a.* — or specify columns ) INSERT INTO <existing_table> –specify columns if necessary SELECT [DISTINCT] * FROM moved_rows; But you want … Read more
The best way is to make sure that you run SELECT COUNT on a single column (SELECT COUNT(*) is slower) – but SELECT COUNT will always be the fastest way to get a count of things (the database optimizes the query internally). If you check out the comments below, you can see arguments for why … Read more
You should cast before you divide, but also you were missing a subquery to get the total count from the table. Here’s the sample. select random_int, count(random_int) as Count, cast(count(random_int) as decimal(7,2)) / cast((select count(random_int) from test) as decimal(7,2)) as Percent from test group by random_int order by random_int;
There are many possible causes for serialization failures. Technically, a deadlock between two transactions is one form of serialization failure, and can potentially happen at any isolation level if there are concurrent modifications to the schema (database structure). Since you’re asking about PostgreSQL, you should be aware that in PostgreSQL this type of serialization failure … Read more
Update 2024-01-17: SQL Fiddle no longer works for Oracle and seems to have lost many old fiddles. See the other answer for a more up-to-date list. SQL Fiddle Here is a trivial example of use: http://sqlfiddle.com/#!4/8cf15/5
The parameter you give to the sqlite3 program is the database file name. To execute commands from a file, you must redirect the input to that file: $ sqlite3 mydatabase.db < SQLTableTransfer or tell it to read from that file: $ sqlite3 mydatabase.db “.read SQLTableTransfer”
declare @D as datetime=”2012-01-02T12:04:11.443″ select dateadd(hour, datediff(hour, 0, @D), 0) select dateadd(minute, datediff(minute, 0, @D), 0)
Yes it is strange and counterintuitive. Hugh Darwen theorises about how this state of affairs came about: Do you take SELECT-FROM-WHERE for granted, or do you, like me, find it rather curious that the System R team should have spurned the normal way of writing expressions of arbitrary complexity in favour of something utterly idiosyncratic … Read more