大约有 40,000 项符合查询结果（耗时：0.0322秒） [XML]
设置用户默认权限 Umask命令详解 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...最终的权限变成了755（777 – 022）。
顺便再介绍一下如何方便的修改目录或文件的权限：
shell> find /path -type d -print0 | xargs -0 chmod 755
shell> find /path -type f -print0 | xargs -0 chmod 644
本次补习班下课！
Umask 默认权限
Differences between MySQL and SQL Server [closed]
...mplementations.
For example, take a look at the top-n section. In MySQL:
SELECT age
FROM person
ORDER BY age ASC
LIMIT 1 OFFSET 2
In SQL Server (T-SQL):
SELECT TOP 3 WITH TIES *
FROM person
ORDER BY age ASC
share
...
How can I make SQL case sensitive string comparison on MySQL?
... @BT To make utf8 column case sensitive you could use bin colation like: SELECT 'email' COLLATE utf8_bin = 'Email'
– piotrekkr
Apr 23 '13 at 11:43
...
Rank function in MySQL
...
One option is to use a ranking variable, such as the following:
SELECT first_name,
age,
gender,
@curRank := @curRank + 1 AS rank
FROM person p, (SELECT @curRank := 0) r
ORDER BY age;
The (SELECT @curRank := 0) part allows the variable initializatio...
How can I get the intersection, union, and subset of arrays in Ruby?
...et operations on arrays by doing &(intersection), -(difference), and |(union).
Obviously I didn't implement the MultiSet to spec, but this should get you started:
class MultiSet
attr_accessor :set
def initialize(set)
@set = set
end
# intersection
def &(other)
@set & o...
How do I split a string so I can access item x?
...0,
PATINDEX('%|%', @products))
SELECT @individual
SET @products = SUBSTRING(@products,
LEN(@individual + '|') + 1,
LEN(@products))
END
ELSE
BEGIN
SET @individu...
MySQL table is marked as crashed and last (automatic?) repair failed
... This was a quick fix! Had a "bad" options table. Make sure that you select the correct database first !
– jyllstuart
Jan 10 '19 at 15:54
add a comment
...
SQL/mysql - Select distinct/UNIQUE but return all columns?
...
You're looking for a group by:
select *
from table
group by field1
Which can occasionally be written with a distinct on statement:
select distinct on field1 *
from table
On most platforms, however, neither of the above will work because the behavior o...
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....
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...