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How to check for valid email address? [duplicate]
...TLD to alphanumeric right now (still haven't seen a TLD that has non-ASCII chars). Using this now: re.compile(r"[^@\s]+@[^@\s]+\.[a-zA-Z0-9]+$")
– gaefan
Aug 29 '15 at 15:39
...
Oracle “(+)” Operator
...dize OUTER joins.
The query would be re-written in ANSI-92 syntax as:
SELECT ...
FROM a
LEFT JOIN b ON b.id = a.id
This link is pretty good at explaining the difference between JOINs.
It should also be noted that even though the (+) works, Oracle recommends not using it:
Oracle re...
ORDER BY the IN value list
... (introduced in PostgreSQL 8.2) VALUES (), ().
Syntax will be like this:
select c.*
from comments c
join (
values
(1,1),
(3,2),
(2,3),
(4,4)
) as x (id, ordering) on c.id = x.id
order by x.ordering
share...
'IF' in 'SELECT' statement - choose output value based on column values
...
SELECT id,
IF(type = 'P', amount, amount * -1) as amount
FROM report
See http://dev.mysql.com/doc/refman/5.0/en/control-flow-functions.html.
Additionally, you could handle when the condition is null. In the case of...
Find rows that have the same value on a column in MySQL
...sses and how many times they're used, with the most used addresses first.
SELECT email,
count(*) AS c
FROM TABLE
GROUP BY email
HAVING c > 1
ORDER BY c DESC
If you want the full rows:
select * from table where email in (
select email from table
group by email having count(*) &g...
Legality of COW std::string implementation in C++11
...be seen in the following if COW were allowed: std::string a("something"); char& c1 = a[0]; std::string b(a); char& c2 = a[1]; c1 is a reference to a. You then "copy" a. Then, when you attempt to take the reference the second time, it has to make a copy to get a non-const reference since...
Can you create nested WITH clauses for Common Table Expressions?
..., the form of the statement you are looking for would be
WITH x AS
(
SELECT * FROM MyTable
),
y AS
(
SELECT * FROM x
)
SELECT * FROM y
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...
Drop all tables whose names begin with a certain string
...n one in the database.
DECLARE @cmd varchar(4000)
DECLARE cmds CURSOR FOR
SELECT 'drop table [' + Table_Name + ']'
FROM INFORMATION_SCHEMA.TABLES
WHERE Table_Name LIKE 'prefix%'
OPEN cmds
WHILE 1 = 1
BEGIN
FETCH cmds INTO @cmd
IF @@fetch_status != 0 BREAK
EXEC(@cmd)
END
CLOSE cmds;
DEA...
How to delete duplicate rows in SQL Server?
... are deleted (or updated), therefore just change the DELETE FROM CTE... to SELECT * FROM CTE:
WITH CTE AS(
SELECT [col1], [col2], [col3], [col4], [col5], [col6], [col7],
RN = ROW_NUMBER()OVER(PARTITION BY col1 ORDER BY col1)
FROM dbo.Table1
)
DELETE FROM CTE WHERE RN > 1
DEMO (re...
Inserting data into a temporary table
...
INSERT INTO #TempTable (ID, Date, Name)
SELECT id, date, name
FROM physical_table
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