大约有 41,000 项符合查询结果（耗时：0.0247秒） [XML]
Generate list of all possible permutations of a string
...re x and y is how you define them and r is the number of characters we are selecting from --if I am understanding you correctly. You should definitely generate these as needed and not get sloppy and say, generate a powerset and then filter the length of strings.
The following definitely isn't the b...
How to fetch the row count for all tables in a SQL SERVER database [duplicate]
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EXEC sp_MSForEachTable @command1='INSERT #counts (table_name, row_count) SELECT ''?'', COUNT(*) FROM ?'
SELECT table_name, row_count FROM #counts ORDER BY table_name, row_count DESC
DROP TABLE #counts
The output will be a list of tables and their row counts.
If you just want the total row count...
How to create Android Facebook Key Hash?
...of your app on facebook. To get there, go to developers.facebook.com/apps, select your app, go to Edit settings and scroll down. After that, wait a few minutes until the changes take effect.
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How to read the output from git diff?
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On my mac:
info diff then select: Output formats -> Context -> Unified format -> Detailed Unified :
Or online man diff on gnu following the same path to the same section:
File: diff.info, Node: Detailed
Unified, Next: Example Unified...
MQTT与TCP的区别 - 创客硬件开发 - 清泛IT社区，为创新赋能！
...问控制、集群、共享订阅、重要指标dashboard、sysadmin api、插件扩展、对topic或session或clientid的tracing调试等高级功能，大大简化服务器端的开发工作量。实际应用中，只需要写发布和订阅接口函数即可，中间过程对应用开发人员透...
ROW_NUMBER() in MySQL
...asy, but actually it kind of isn't).
I often plump for a null-self-join:
SELECT t0.col3
FROM table AS t0
LEFT JOIN table AS t1 ON t0.col1=t1.col1 AND t0.col2=t1.col2 AND t1.col3>t0.col3
WHERE t1.col1 IS NULL;
“Get the rows in the table for which no other row with matching col1,col2 has a hi...
Why is the gets function so dangerous that it should not be used?
...deal would have been to have a "string pointer" identify a byte that would select among a few different string/buffer/buffer-info formats, with one value of prefix byte indicating a struct that contained the prefix byte [plus padding], plus the buffer size, used size, and address of the actual text....
How to drop SQL default constraint without knowing its name?
...MySchema'
set @table_name = N'Department'
set @col_name = N'ModifiedDate'
select @Command = 'ALTER TABLE ' + @schema_name + '.[' + @table_name + '] DROP CONSTRAINT ' + d.name
from sys.tables t
join sys.default_constraints d on d.parent_object_id = t.object_id
join sys.columns c on c.object_id ...
Why do we need fibers
... each. Think about it: normally all the Enumerable methods, including map, select, include?, inject, and so on, all work on the elements yielded by each. But what if an object has other iterators other than each?
irb(main):001:0> "Hello".chars.select { |c| c =~ /[A-Z]/ }
=> ["H"]
irb(main):00...
How do you convert a byte array to a hexadecimal string, and vice versa?
... }
return result;
}
static uint[] _Lookup32 = Enumerable.Range(0, 255).Select(i => {
string s = i.ToString("X2");
return ((uint)s[0]) + ((uint)s[1] << 16);
}).ToArray();
static string ByteArrayToHexViaLookupPerByte(byte[] bytes) {
var result = new char[bytes.Length * 2];
...