大约有 13,000 项符合查询结果（耗时：0.0191秒） [XML]
Calendar Recurring/Repeating Events - Best Storage Method
... grabbing the events for the day it's at, the query would look like this:
SELECT EV.*
FROM `events` EV
RIGHT JOIN `events_meta` EM1 ON EM1.`event_id` = EV.`id`
RIGHT JOIN `events_meta` EM2 ON EM2.`meta_key` = CONCAT( 'repeat_interval_', EM1.`id` )
WHERE EM1.meta_key = 'repeat_start'
AND (
...
Counting DISTINCT over multiple columns
... function turns the ints into varchars to make the distinct more reliable
SELECT COUNT(DISTINCT (CHECKSUM(DocumentId,DocumentSessionId)) + CHECKSUM(REVERSE(DocumentId),REVERSE(DocumentSessionId)) )
FROM DocumentOutPutItems
...
Append column to pandas dataframe
...efore you join() or concat() if you trying to deal with some data frame by selecting some rows from another DataFrame.
One example below shows some interesting behavior of join and concat:
dat1 = pd.DataFrame({'dat1': range(4)})
dat2 = pd.DataFrame({'dat2': range(4,8)})
dat1.index = [1,3,5,7]
dat...
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...
PHP method chaining?
...imed at creating a DSL. Ex: $foo->setBar(1)->setBaz(2) vs $table->select()->from('foo')->where('bar = 1')->order('ASC). The latter spans multiple objects.
– Gordon
Sep 16 '10 at 7:32
...
Get Substring - everything before certain char
...have moved on a bit since this thread started.
Now, you could use
string.Concat(s.TakeWhile((c) => c != '-'));
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How can you determine how much disk space a particular MySQL table is taking up?
...
For a table mydb.mytable run this for:
BYTES
SELECT (data_length+index_length) tablesize
FROM information_schema.tables
WHERE table_schema='mydb' and table_name='mytable';
KILOBYTES
SELECT (data_length+index_length)/power(1024,1) tablesize_kb
FROM information_schema....
How do I create a PDO parameterized query with a LIKE statement?
...
Figured it out right after I posted:
$query = $database->prepare('SELECT * FROM table WHERE column LIKE ?');
$query->execute(array('value%'));
while ($results = $query->fetch())
{
echo $results['column'];
}
...
How to Concatenate Numbers and Strings to Format Numbers in T-SQL?
...
select 'abcd' + ltrim(str(1)) + ltrim(str(2))
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LINQ - Full Outer Join
...rst.ID equals last.ID into temp
from last in temp.DefaultIfEmpty()
select new
{
first.ID,
FirstName = first.Name,
LastName = last?.Name,
};
var rightOuterJoin =
from last in lastNames
join first in firstNames on last.ID equals first.ID into temp
fr...