大约有 5,887 项符合查询结果（耗时：0.0421秒） [XML]
How should you build your database from source control?
...sing automation - or should production by built by copying objects from a stable, finalized test environment?
Automation for both. Do NOT copy data between the environments
How do you deal with potential differences between test and production environments in deployment scripts?
Use templates, so th...
Create an empty data.frame
...
You could use read.table with an empty string for the input text as follows:
colClasses = c("Date", "character", "character")
col.names = c("Date", "File", "User")
df <- read.table(text = "",
colClasses = colClasses,
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How to drop columns by name in a data frame
...
I tried to delete a column while using the package data.table and got an unexpected result. I kind of think the following might be worth posting. Just a little cautionary note.
[ Edited by Matthew ... ]
DF = read.table(text = "
fruit state grade y1980 y1990 y2000
app...
Binary Data in MySQL [closed]
...
For a table like this:
CREATE TABLE binary_data (
id INT(4) NOT NULL AUTO_INCREMENT PRIMARY KEY,
description CHAR(50),
bin_data LONGBLOB,
filename CHAR(50),
filesize CHAR(50),
filetype CHAR(50)
);
Here is...
Using a .php file to generate a MySQL dump
... or less are auto-explicative:
$dumpSettingsDefault = array(
'include-tables' => array(),
'exclude-tables' => array(),
'compress' => 'None',
'no-data' => false,
'add-drop-database' => false,
'add-drop-table' => false,
'single-transaction' => true,
...
How can an html element fill out 100% of the remaining screen height, using css only?
... is where magic comes into picture - since we have 'min-height' on playing table, we are telling browser that <body> is superior over <html> because <body> holds the min-height. This in turn, allows <body> to override <html> because <html> had height already earli...
Creating stored procedure and SQLite?
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Yet, it is possible to fake it using a dedicated table, named for your fake-sp, with an AFTER INSERT trigger. The dedicated table rows contain the parameters for your fake sp, and if it needs to return results you can have a second (poss. temp) table (with name related to t...
What is the difference between ExecuteScalar, ExecuteReader and ExecuteNonQuery?
...ny result set with multiple rows/columns (e.g., SELECT col1, col2 from sometable).
ExecuteNonQuery is typically used for SQL statements without results (e.g., UPDATE, INSERT, etc.).
share
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improve...
convert_tz returns null
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This will happen if you haven't loaded the time zone table into mysql.
mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root -p mysql
mysql is the name of the built-in database that holds MySQL-specific configuration data.
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How to vertically center a div for all browsers?
I want to center a div vertically with CSS. I don't want tables or JavaScript, but only pure CSS. I found some solutions, but all of them are missing Internet Explorer 6 support.
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