大约有 30,000 项符合查询结果（耗时：0.0505秒） [XML]
Select datatype of the field in postgres
... ?
For example
I have the following table,
student_details (
stu_id integer,
stu_name varchar(30 ),
joined_date timestamp
);
...
Origin is not allowed by Access-Control-Allow-Origin
...ery likely exposes your users to attack. If you don't know that you specifically need to use a wildcard, you should not use it, and instead you should whitelist your specific domain:
<?php header('Access-Control-Allow-Origin: http://example.com') ?>
...
How do I find duplicate values in a table in Oracle?
...XISTS (
SELECT 1 FROM TABLE
WHERE COLUMN_NAME = A.COLUMN_NAME
AND ROWID < A.ROWID
)
Works fine (quick enough) when there is index on column_name. And it's better way to delete or update duplicate rows.
share
...
Is there a CSS selector for elements containing certain text?
... consider as important to base styling on. Right now our html content typically is tightly paired to the css by including classes that we know the styler cares about. They are already shifting towards letting CSS at the content, as evidenced by attribute value selectors in CSS3.
...
How do I get textual contents from BLOB in Oracle SQL
I am trying to see from an SQL console what is inside an Oracle BLOB.
11 Answers
11
...
MongoDB atomic “findOrCreate”: findOne, insert if nonexistent, but do not update
as the title says, I want to perform a find (one) for a document, by _id, and if doesn't exist, have it created, then whether it was found or was created, have it returned in the callback.
...
How is std::function implemented?
...ally implemented by the compiler creating a class with overloaded function call operator and the referenced variables as members. This suggests that the size of lambda expressions varies, and given enough references variables that size can be arbitrarily large .
...
Difference between CC, gcc and g++?
... AIX, the system C compiler goes by names such as 'xlc' or 'xlc32'.
Classically, the default system compiler was called 'cc' and self-configuring software falls back on that name when it doesn't know what else to use.
POSIX attempted to legislate its way around this by requiring the programs c89 (...
rails 3 validation on uniqueness on multiple attributes
...
In Rails 2, I would have written:
validates_uniqueness_of :zipcode, :scope => :recorded_at
In Rails 3:
validates :zipcode, :uniqueness => {:scope => :recorded_at}
For multiple attributes:
validates :zipcode, :uniqueness => {:scope => [:recor...
Is it safe to remove selected keys from map within a range loop?
...y := range (m) { if key % 2 == 0 { /* this is just some condition, such as calling expired */ delete(m, key); } }
– abanana
Jan 19 '17 at 15:40
...