大约有 13,000 项符合查询结果（耗时：0.0280秒） [XML]
Select by partial string from a pandas DataFrame
...ns of which 2 contain string values. I was wondering if there was a way to select rows based on a partial string match against a particular column?
...
Is it possible to GROUP BY multiple columns using MySQL?
Is it possible to GROUP BY more than one column in a MySQL SELECT query? For example:
7 Answers
...
How can I combine multiple rows into a comma-delimited list in Oracle? [duplicate]
...countries values ('Andorra');
insert into countries values ('Antigua');
SELECT SUBSTR (SYS_CONNECT_BY_PATH (country_name , ','), 2) csv
FROM (SELECT country_name , ROW_NUMBER () OVER (ORDER BY country_name ) rn,
COUNT (*) OVER () cnt
FROM countries)
WHE...
How to find gaps in sequential numbering in mysql?
...r
Here's version that works on table of any size (not just on 100 rows):
SELECT (t1.id + 1) as gap_starts_at,
(SELECT MIN(t3.id) -1 FROM arrc_vouchers t3 WHERE t3.id > t1.id) as gap_ends_at
FROM arrc_vouchers t1
WHERE NOT EXISTS (SELECT t2.id FROM arrc_vouchers t2 WHERE t2.id = t1.id + ...
MySQL DROP all tables, ignoring foreign keys
... these tweaks:
Limit the generated drops to your database like this:
SELECT concat('DROP TABLE IF EXISTS `', table_name, '`;')
FROM information_schema.tables
WHERE table_schema = 'MyDatabaseName';
Note 1: This does not execute the DROP statements, it just gives you a list of them. You will n...
Datetime equal or greater than today in MySQL
...
SELECT * FROM users WHERE created >= CURDATE();
But I think you mean created < today
share
|
improve this answer
...
Permutations in JavaScript?
... arr.splice(i, 1);
if (arr.length === 0) {
results.push(memo.concat(cur));
}
permute(arr.slice(), memo.concat(cur));
arr.splice(i, 0, cur[0]);
}
return results;
}
return permute(inputArr);
}
Adding an ES6 (2015) version. Also does not mutate the origin...
.NET / C# - Convert char[] to string
... 'o', 'c', 'k', '-', '&', '-', 'R', 'o', 'l', 'l' };
string s = String.Concat( c );
Debug.Assert( s.Equals( "Rock-&-Roll" ) );
share
|
improve this answer
|
follow
...
How To Test if Type is Primitive
...
where t.IsValueType
select typeof (Nullable<>).MakeGenericType(t);
List = types.Concat(nullTypes).ToArray();
}
public static bool Test(Type type)
{
if (List.Any(x => x.IsAssignableFrom(type))...
How can I return pivot table output in MySQL?
...OUP BY.
The basic SQL providing this pivot can look something like this:
SELECT P.`company_name`,
COUNT(
CASE
WHEN P.`action`='EMAIL'
THEN 1
ELSE NULL
END
) AS 'EMAIL',
COUNT(
CASE
WHEN P.`action`='PRINT' AND...