大约有 5,883 项符合查询结果（耗时：0.0169秒） [XML]
Create an empty data.frame
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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
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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]
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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,
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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.).
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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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How to detect the end of loading of UITableView
I want to change the offset of the table when the load is finished and that offset depends on the number of cells loaded on the table.
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