PHP library for processing Excel documents, which can insert text, text symbols, paging, headers/footers, tables, elements in lists, hyperlinks, etc. PHPExcel is equipped with more than a dozen practical examples that can be used as development references, and is equipped with corresponding Chinese documents, which is very convenient to use<?php /** PHPExcel root directory */ if (!defined('PHPEXCEL_ROOT')) {     define('PHPEXCEL_ROOT', dirname(__FILE__) . '/');     require(PHPEXCEL_ROOT . 'PHPExcel/Autoloader.php'); } class PHPExcel {     private $uniqueID;     private $properties;     private $security;     private $workSheetCollection = array();     private $calculationEngine;     private $activeSheetIndex = 0;     private $namedRanges = array();     private $cellXfSupervisor;     private $cellXfCollection = array();     private $cellStyleXfCollection = array();     private $hasMacros = false;     private $macrosCode;     private $macrosCertificate;     private $ribbonXMLData;     private $ribbonBinObjects;     public function hasMacros()     {         return $this->hasMacros;     }     public function setHasMacros($hasMacros = false)     {         $this->hasMacros = (bool) $hasMacros;     }     public function setMacrosCode($MacrosCode = null)     {         $this->macrosCode=$MacrosCode;         $this->setHasMacros(!is_null($MacrosCode));     }     public function getMacrosCode()     {         return $this->macrosCode;     }     public function setMacrosCertificate($Certificate = null)     {         $this->macrosCertificate=$Certificate;     }

PHP library for operating Excel documents, you can insert text, text symbols, paging, headers/footers, tables, elements in lists, hyperlinks, etc. PHPExcel is equipped with more than a dozen practical examples that can be used as development references, and is equipped with corresponding Chinese documents, which is very convenient to use<?php namespace ExcelAnt\Style; use ExcelAnt\Style\StyleTestCase,     ExcelAnt\Style\Alignment; class AlignmentTest extends StyleTestCase {     public function testSetVerticalWithWrongParameter($param)     {         $alignment = (new Alignment())->setVertical($param);     }     public function testSetAndGetVertical()     {         $alignment = (new Alignment())->setVertical(Alignment::VERTICAL_BOTTOM);         $this->assertEquals(Alignment::VERTICAL_BOTTOM, $alignment->getVertical());     }     public function testSetHorizontalWithWrongParameter($param)     {         $alignment = (new Alignment())->setHorizontal($param);     }     public function testSetAndGetHorizontal()     {         $alignment = (new Alignment())->setHorizontal(Alignment::HORIZONTAL_LEFT);         $this->assertEquals(Alignment::HORIZONTAL_LEFT, $alignment->getHorizontal());     } }

Database migration (also known as hierarchical storage management, hsm) is a technology that integrates offline storage and online storage. It uses high-speed, high-capacity off-line storage devices as the next-level devices of disk devices, and then automatically migrates commonly used data in disks to secondary large-capacity storage devices such as tape libraries (tape libraries for short) according to specified policies. When the data needs to be used, the hierarchical storage system will automatically transfer the data from the lower-level storage device back to the upper-level disk. For users, the above-mentioned data migration operation is completely transparent, except that the speed of accessing the disk is slightly slow, and the capacity of the logical disk is obviously greatly improved. This is the archiving process of moving rarely used or unused files to a secondary storage system such as tape or optical disk. These files are typically image documents or historical information that need to be easily accessible at any time in the future. The migration effort is integrated with the backup strategy, and regular backups are still required. It also includes computer data migration, migrating data, applications, and personalized settings from the old computer (old system) to the new computer (new system), which is necessary after the system upgrade.

The implementation of management migration can be divided into three stages: preparation before management migration, implementation of management migration, and verification after management migration. Due to the characteristics of management migration, a large amount of work needs to be completed in the preparation stage. Sufficient and thoughtful preparation is the main basis for completing management migration. Specifically, it is necessary to provide a detailed description of the data source to be migrated (including the storage method of the data, the amount of data, and the time span of the data); to establish a data dictionary of the old and new system databases; to conduct a quality analysis of the historical data of the old system, and to Difference analysis of structures; Difference analysis of code data between the old and new systems; Establishing mapping relationships between database tables of the old and new systems, and handling methods for fields that cannot be mapped; Developing and deploying ETL tools, writing test plans and verification procedures for data conversion; formulating data Conversion contingency measures.

"Exchange rate" is abbreviated as ExRate, also known as "foreign exchange rate", "foreign exchange market" or "exchange rate", etc. EXRATE is the abbreviation of "Exchange Rate" in English. It is the ratio of one currency to another currency, and it is the price of one currency expressed in another currency. Since the currencies of various countries (regions) in the world have different names and currency values, one currency must set an exchange rate for the currencies of other countries (or regions), that is, the exchange rate. In the short term, the exchange rate of a country (or region) is determined by the demand and supply of the country's (or region's) currency in exchange for foreign currency. Foreigners buying domestic goods, investing in the country, and investing in the domestic currency affect the demand for the domestic currency. Domestic residents want to buy foreign products, invest in foreign countries, and foreign exchange speculation affect the country's money supply. In the long run, the main factors that affect the exchange rate are: relative price levels, tariffs and quotas, preference for domestic goods relative to foreign goods, and productivity.

GeoJSON is a format for encoding various geographical data structures, a geospatial information data exchange format based on Javascript object representation. GeoJSON objects can represent geometries, features, or feature collections. GeoJSON supports the following geometry types: point, line, polygon, multipoint, multiline, polygon, and geometry collection. Features in GeoJSON include a geometric object and other attributes, and feature collections represent a series of features. A complete GeoJSON data structure is always an object (in JSON terms). In GeoJSON, objects are composed of name/value pairs - also called collections of members. For each member, the name is always a string. The value of a member is either a string, a number, an object, an array, or one of the following text constants: "true", "false", and "null". Arrays are composed of elements whose values ​​are as mentioned above. GeoJSON always consists of a single object. This object (referring to the GeoJSON object below) represents a geometry, feature, or collection of features.

MongoDB is a product between a relational database and a non-relational database. It is the most feature-rich among non-relational databases and is most similar to a relational database. The data structure it supports is very loose and is a bson format similar to json, so it can store more complex data types. The biggest feature of Mongo is that the query language it supports is very powerful. Its syntax is somewhat similar to an object-oriented query language. It can almost implement most functions similar to single-table queries in relational databases, and it also supports indexing of data.

A class library is a comprehensive collection of object-oriented reusable types, including interfaces, abstract classes, and concrete classes. Class libraries can solve a range of common programming tasks (including tasks such as string management, data collection, database connections, and file access), as well as a variety of specialized development tasks (console applications, desktop applications, WEB applications, etc. )

PECL's full name is The PHP Extension Community Library, which is an open PHP extension library repository packaged and installed through the PEAR (PHP Extension and Application Repository, PHP Extension and Application Repository) packaging format. PECL modules can be downloaded and installed through the installation management method of PEAR's Package Manager. Unlike most previous PEAR packages, the PECL extension contains C language code that can be compiled into PHP Core. Therefore, the PECL extension library can be compiled into a dynamically loadable .so shared library, or statically compiled with the PHP source. The code is compiled into a method that can be extended. The PECL extension library includes many PHP extension modules for XML parsing, database access, email parsing, embedded Perl and Pthyon script interpreter, etc. Therefore, in a sense, PECL's operating efficiency is higher than many previous ones. PEAR extension library

SSH is the abbreviation of Secure Shell, which was developed by the Network Working Group of IETF; SSH is a security protocol based on the application layer. SSH is currently the most reliable protocol designed to provide security for remote login sessions and other network services. Using the SSH protocol can effectively prevent information leakage during remote management. SSH was originally a program on UNIX systems and quickly expanded to other operating platforms. SSH, when used correctly, can close holes in your network. SSH clients are available for a variety of platforms. Almost all UNIX platforms—including HP-UX, Linux, AIX, Solaris, Digital UNIX, Irix, and others—can run SSH.

JSON (JavaScript Object Notation, JS Object Markup) is a lightweight data exchange format. It is based on a subset of ECMAScript (the js specification developed by w3c) and uses a text format that is completely independent of programming languages ​​to store and represent data. Simplicity and clear hierarchical structure make JSON an ideal data exchange language. It is easy for people to read and write, and it is also easy for machines to parse and generate, and effectively improves network transmission efficiency.

Data set, also known as data set, data set or data set, is a collection composed of data. Data set (or dataset) is a collection of data, usually in tabular form. Each column represents a specific variable. Each row corresponds to a question for a certain member of the data set. It lists the values ​​for each variable, such as the height and weight of an object or the value of a random number. Each numerical value is called a data point. Corresponding to the number of rows, the data for this dataset may include one or more members.