How to call thinkphp's db class

ThinkPHP is a lightweight development framework based on MVC architecture. It provides a wealth of tools and components to facilitate developers to quickly build Web applications. Among them, database operation is the most common task in Web application development. Therefore, ThinkPHP also provides a convenient database operation class-DB class.

This article will introduce in detail how to call ThinkPHP's DB class. The specific content is as follows:

1. Overview

1.1 What is the DB class

The DB class is a database operation class, which encapsulates the operation method of the database to facilitate our operation database.

1.2 Features of ThinkPHP’s DB class

(1) Simple and easy to use: ThinkPHP’s DB class provides a concise, easy-to-understand, and easy-to-use interface, which reduces the complexity of the code and improves the efficiency of the code. Code readability and maintainability.

(2) Strong cross-platform capability: ThinkPHP’s DB class supports a variety of database operations, such as MySQL, Oracle, SqlServer, etc., and can run on different platforms.

(3) Support chain operation: Through chain operation, you can write code more conveniently and reduce the redundancy of code.

2. Calling method

2.1 Connect to the database

Before using the DB class to operate the database, you need to establish a database connection first. The method to connect to the database is as follows:

$db = db('表名');

Among them, 'table name' is the name of the table to be operated in the database, and the DB object is returned through this method.

2.2 Query operation

(1) Query all records

The method of querying all records is as follows:

$list = $db->select();

This method returns a query containing all query results Two-dimensional array.

(2) Conditional query

The method of conditional query is as follows:

$list = $db->where('字段名=值')->select();

This method returns a two-dimensional array containing query results that meet the conditions.

(3) Paging query

The method of paging query is as follows:

$list = $db->limit($firstRow,$listRows)->select();

Among them, $firstRow represents the starting position of each page, and $listRows represents the starting position of each page. Records.

(4) Sorting query

The method of sorting query is as follows:

$list= $db->order('字段名 asc')->select();

This method returns a two-dimensional array of query results sorted according to the specified field.

(5) Statistical query

The statistical query method is as follows:

$count= $db->count();

This method returns the number of records that meet the conditions.

2.3 New operation

The method of new operation is as follows:

$data = ['字段名'=>'值'];
$result = $db->insert($data);

Among them, $data represents the new data, and $result is the result of the new operation, returned Value is true or false.

2.4 Update operation

The update operation method is as follows:

$data = ['字段名'=>'值'];
$result = $db->where('条件')->update($data);

Among them, $data represents the updated data, $result is the result of the update operation, and the return value is true or false.

2.5 Delete operation

The method of deletion operation is as follows:

$result = $db->where('条件')->delete();

Among them, $result is the result of the deletion operation, and the return value is true or false.

3. Summary

Through the introduction of this article, we have learned about the calling methods of ThinkPHP's DB class, and mastered common database operation methods such as query, add, update, and delete operations. The DB class is easy to use, cross-platform, and supports chain operations. It is a good helper for us to perform database operations.

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