Chapter Three: Basic bash shell commandsThe Bash program uses command-line arguments to modify the type of shell being started
Parameters
Describe
-C string
Read the commands from a string and process them
Gets the current time in Java for the current system time in Java. Get the current system time and date and format the output:Import Java.util.Date;Import Java.text.SimpleDateFormat;public class Nowstring {public static void Main (string[] args)
1. Group function Usage Rules
group functions in MySQL can be used at will in a SELECT statement, but in Oracle if there is a group function in the query, the other column names must be processed by the group function, or the column in the GROUP BY
1. Group function Usage RulesThe group functions in MySQL are freely available in the SELECT statement, but in Oracle if there is a group function in the query statement, the other column names must be processed by the group function, or the columns
OracleOracle can run on all major platforms (including Windows). Full support for all industry standards. Adopt a fully open strategy. Enables customers to choose the solution that best suits them. Full support for developers, Oracle parallel
JAVASCRIPT Object and attribute SCRIPT tag
Contains JavaScript code.
Syntax
Attribute
LANGUAGE-defined scripting LANGUAGE
SRC defines a URL to specify the file ending with. JS
Windows objects
The top-level object of each HTML
Query JavaScript objects, attributes, and event manuals. It is convenient for friends who learn JavaScript.
Windows objectsThe top-level object of each HTML document.
Attribute
Frames [] sublists array. Each sublists array is stored in the order
Use the mysqldump command to back up the MySQL database script (without a comment version, suitable for production environments)
Use the mysqldump command to back up the MySQL database script (without a comment version, suitable for production
1. DateTime numeric typeSystem. DateTime currentTime = new System. DateTime ();1.1 take the current year, month, day, hour, minute, secondCurrentTime = System. DateTime. Now;1.2 get current yearInt Year = currentTime. Year;1.3 take the current
GUID: The globally unique Identifier (globally unique identifier) is also known as the UUID (universally unique Identifier).
A GUID is a 128-bit numeric identifier produced by a particular algorithm that indicates the uniqueness of the product.
Python log format output and time format
formatter = logging.Formatter("%(asctime)s %(levelname)s %(message)s","%Y%b%d-%H:%M:%S")
The above % Y and so on are time formats, so to understand the above, Let's first look at the Python time format.
%
Php provides several solutions to generate a unique id. I checked it online and found many methods: 1. md5 (time (). mt_rand (); this method has a certain probability that there will be duplicates. 2. the php built-in function uniqid () has been
The real-time display time on the webpage not only adds color to the webpage, but also helps the viewer master the current time. in order to improve the website development speed, the main code can be encapsulated in a separate function and called
This article mainly introduces the Python time operation examples, such as taking the last few days, the last few days, the last 30 days, and the last 30 days, and the last 30 days. For more information, see 1. Method of taking the past time:
The
Uniqid () function usage of PHP and phpuniqid function usage
This example describes how to use the uniqid () function in PHP. Share it with you for your reference. The specific method is analyzed as follows:
The uniqid () function generates a unique
SCRIPT tag
Contains JavaScript code.
Syntax
Attribute
LANGUAGE-defined scripting LANGUAGE
SRC defines a URL to specify the file ending with. JS
Windows objects
The top-level object of each HTML document.
Attribute
Frames [] sublists array. Each
1. Method for retrieving the specific time in the past:Copy codeThe Code is as follows:#! /Usr/bin/python
Import time# Obtain the current time of the previous dayTime. strftime ('% Y-% m-% d % t', time. localtime (time. time ()-24*60*60 ))
# Obtain
This article mainly introduces the usage of uniqid () function in PHP, including the basic usage and Application Analysis of the function, which is a very practical technique. For more information, see
This article mainly introduces the usage of
The difference between the Oracle database and the MySQL database is what we will introduce in this article, hoping to help you. 1. group function usage rules: Group functions in mysql can be used at will in select statements. However, if a group
Oracle Database-DML (data operation language), oracle-dml DML: data operation languageNote: In addition, deletion, modification, and query, the query is the most important, the core, and the most gold content.That is to say, this section! ImportantI.
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