Development of lightweight database SQLite combined with PHP_PHP tutorial

SQLite is a lightweight database. Its design target is embedded, and it has been used in many embedded products. It occupies very low resources. In embedded devices, it may only require a few One hundred K of memory is enough. It can support mainstream operating systems such as Windows/Linux/Unix, and can be combined with many programming languages, such as Tcl, php(as the current mainstream development language), Java, etc., and ODBC The interface is also faster than MySQL (the best combination with PHP) and PostgreSQL, two world-famous open source database management systems.

Although SQLite is very small, the SQL statements it supports are not inferior to other open source databases. The SQL it supports includes:

ATTACH DATABASE
BEGIN TRANSACTION
comment
COMMIT TRANSACTION
COPY
CREATE INDEX
CREATE TABLE
CREATE TRIGGER
CREATE VIEW
DELETE
DETACH DATABASE
DROP INDEX
DROP TABLE
DROP TRIGGER
DROP VIEW
END TRANSACTION
EXPLAIN
expression
INSERT
ON CONFLICT clause
PRAGMA
REPLACE
ROLLBACK TRANSACTION
SELECT
UPDATE

At the same time, it also supports transaction processing functions and more. Some people also say that it is like Microsoft's access (favorite for small websites) . Sometimes it feels a bit similar, but in fact they are very different. For example, SQLite supports cross-platform, is easy to operate, and can directly create databases in many languages. It does not require the support of Office like access(a favorite of small websites). If you have a very small application, or you want to do embedded development and do not have a suitable database system, then you can consider using SQLite now. Its latest version is currently 3.2.2, and its official website is: http://www.sqlite.org, where you can obtain source code and documentation. At the same time, because the database structure is simple and there is not much system source code, it is also suitable for professionals who want to study database system development.

Now we start with a brief introduction. Mainly I want to clarify a few issues, one is how to install and use, and the other is how to combine with php(as the current mainstream development language) development.

1. Installation

1. Windows platform

Download the file under windows, which is actually a command line program (download address: http://www.sqlite. org/sqlite-3_2_2.zip), this command line program is used to generate database files, execute SQL queries, backup databases, etc.
After downloading, for example, if we unzip it to the directory D:Downloadssqlitesqlite-3_2_2, then we enter cmd and enter the directory:
cd D:Downloadssqlitesqlite-3_2_2
D:Downloadssqlitesqlite-3_2_2>sqlite3 test. db
# If test.db does not exist, then a database file is generated. If it exists, use the database file directly, which is equivalent to use (the best combination with PHP) 🎜>SQLite version 3.2.2
Enter ".help" for instructions
sqlite>
# SQLite prompt. If you want to view command help, enter .help. In sqlite, all system commands start with . of:
sqlite> .help
.databases List names and files of attached databases
.dump ?TABLE? ... Dump the database in an SQL text format
.echo ON|OFF Turn command echo on or off
.exit Exit this program
.explain ON|OFF Turn output mode suitable for EXPLAIN on or off.
.header(s) ON|OFF Turn display of headers on or off
.help                Show this message
.import FILE TABLE       Import data from FILE into TABLE
.indices TABLE         Show names of all indices on TABLE                           

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