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How to change MySQL column definition?
I have a mySQL table called test:
3 Answers
3
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Simulate CREATE DATABASE IF NOT EXISTS for PostgreSQL?
...k around it from within psql by executing the DDL statement conditionally:
SELECT 'CREATE DATABASE mydb'
WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = 'mydb')\gexec
The manual:
\gexec
Sends the current query buffer to the server, then treats each column of each row of the query's outpu...
How to change the color of an svg element?
...create a font out of the SVG using a service like https://icomoon.io/app/#/select or such. upload your SVG, click "generate font", include font files and css into your side and just use and style it like any other text. I always use it like this because it makes styling much easier.
EDIT: As mentio...
Where can I download english dictionary database in a text format? [closed]
... replace the deprecated syntax before running it against a 5.0+ version of MySQL
– Serguei Fedorov
Aug 16 '18 at 2:10
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Commit changes to a different branch than the currently checked out branch with subversion
... It must not be the root of the repository, less to duplicate in that way;
Select TortoiseSVN -> "Branch/tag...";
Set To URL: "svn://host/repository/FooBar/branches/FooBarBranchName";
Make sure [*] Working copy is selected. This will ensure the changes are commited;
Log message: "Experimenting wi...
Getting attributes of a class
...dict = {**type(mc).__dict__, **mc.__dict__}
# Or Python < 3.5
def dict_union(d1, d2):
z = d1.copy()
z.update(d2)
return z
combined_dict = dict_union(type(mc).__dict__, mc.__dict__)
attributes = [a for a, v in combined_dict.items()
if not re.match('<function.*?>'...
Case conventions on element names?
...inent examples:
<a>1</a><b>1</b>
<xsl:value-of select="a+b"/>
outputs 2, as expected
<a>1</a><b>1</b>
<xsl:value-of select="a-b"/>
DOES NOT ERROR, BUT OUTPUTS NOTHING AT ALL
In the above code, you must put at least one space before a su...
count(*) vs count(column-name) - which is more correct? [duplicate]
...
there is a performance difference (at least in MySQL) as well (see my answer).
– nickf
Jun 9 '10 at 7:51
1
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Computed / calculated / virtual / derived columns in PostgreSQL
...y as column?
The expression (looking like a column) is not included in a SELECT * FROM tbl, though. You always have to list it explicitly.
Can also be supported with a matching expression index - provided the function is IMMUTABLE. Like:
CREATE FUNCTION col(tbl) ... AS ... -- your computed expr...
【最全】CSS响应式布局的5种实现方式 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...整代码与文件 可进入粉丝群获取 ！
三、rem 布局
1、rem 如何适配
rem 是相对于 html 根元素的字体大小的单位。
我们通过修改 html 中 font-size 的字体大小来控制 rem 的大小。
比如：
html {
font-size: 10px;
}
.box {
width: 10rem;
...