大约有 42,000 项符合查询结果(耗时:0.0414秒) [XML]
MySQL case sensitive query [duplicate]
...ing for 'value'. However it will return 'VALUE', 'value', 'VaLuE', etc…
SELECT * FROM `table` WHERE `column` = 'value'
The good news is that if you need to make a case-sensitive query, it is very easy to do using the BINARY operator, which forces a byte by byte comparison:
SELECT * FROM `table...
GROUP BY to combine/concat a column [duplicate]
...
SELECT
[User], Activity,
STUFF(
(SELECT DISTINCT ',' + PageURL
FROM TableName
WHERE [User] = a.[User] AND Activity = a.Activity
FOR XML PATH (''))
, 1, 1, '') AS URL...
Why is there “data” and “newtype” in Haskell? [duplicate]
...rcher | Accountant
data Race = Human | Elf | Orc | Goblin
data PlayerCharacter = PlayerCharacter Race Profession
When using newtype, you're restricted to just one constructor with one
field.
Now consider the following type:
data CoolBool = CoolBool { getCoolBool :: Bool }
...
How to play with Control.Monad.Writer in haskell?
...ype of logNumber is logNumber :: (Show a, Monad m) => a -> WriterT [[Char]] m a for me.
– kmikael
May 27 '15 at 20:15
...
How can I easily convert DataReader to List? [duplicate]
... writing an extension method for this:
public static IEnumerable<T> Select<T>(this IDataReader reader,
Func<IDataReader, T> projection)
{
while (reader.Read())
{
yield return projection(reader);
}
}
You can then use LINQ...
Create batches in linq
... int maxItems)
{
return items.Select((item, inx) => new { item, inx })
.GroupBy(x => x.inx / maxItems)
.Select(g => g.Select(x => x.item));
}
}
and the usage would be:
List<int> list = new L...
How to sort the result from string_agg()
...
With postgres 9.0+ you can write:
select string_agg(product,' | ' order by product) from "tblproducts"
Details here.
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Remove duplicates in the list using linq
...
var distinctItems = items.GroupBy(x => x.Id).Select(y => y.First());
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Why is unsigned integer overflow defined behavior but signed integer overflow isn't?
....6.1:3:
Values stored in unsigned bit-fields and objects of type unsigned char shall be represented using a pure binary notation.
C99 6.2.6.2:2:
If the sign bit is one, the value shall be modified in one of the following ways:
— the corresponding value with sign bit 0 is negated (sign and magni...
Escaping keyword-like column names in Postgres
...). A delimited identifier is always an
identifier, never a key word. So "select" could be used to refer to a
column or table named "select", whereas an unquoted select would be
taken as a key word and would therefore provoke a parse error when
used where a table or column name is expected.
...
