Add, delete, modify, and query operations in the CI (CodeIgniter) Framework _ php instance

First, create a model (project directory models). Note: The model name is the same as the file name and must inherit the data core class CI_Model, And the constructor in the parent class must be reloaded. CodeIgniter's data function class is in \ system \ database \ DB_active_rec.php

The Code is as follows:

Class ModelName extends CI_Model
{
Function _ construct ()
{
Parent: :__ construct ();
}
}

Connect to the database: $ this-> load-> database ();

The Code is as follows:

ClassModel_name extends CI_Model
{
Function _ construct ()
{
Parent: :__ construct ();
$ This-> load-> database ();
}
}

Written in the model constructor, so that the model can be loaded and connected to the database, which is very convenient.

Insert data

The Code is as follows:

$ This-> db-> insert ($ tableName, $ data );
$ TableName = indicates the name of the table to be operated.
$ Data = the data you want to insert, which is inserted as an array (key name = field name, key value = field value, auto-incrementing primary key does not need to be written ).

Update Data

The Code is as follows:

$ This-> db-> where ('field name', 'field value ');
$ This-> db-> update ('table name', an array of modified values );

Query data

The Code is as follows:

$ This-> db-> where ('field name', 'field value ');
$ This-> db-> select ('field ');
$ Query = $ this-> db-> get ('table name ');
Return $ query-> result ();

Delete data

The Code is as follows:

$ This-> db-> where ('field name', 'field value ');
$ This-> db-> delete ('table name ');

Next, we need to call our model in the controller.

The Code is as follows:

$ This-> load-> model ('model name') // Model name refers to the model you created under the project directory/models/(same as the file name)
$ This-> model name-> method name

To avoid calling each controller method once. I did this.

The Code is as follows:

Class ControllerName extends CI_Controller
{
Function _ construct ()
{
Parent: :__ construct ();
$ This-> load-> model ('model name ');
}
}