CodeIgniter uses Active Record Class for database action.Active Record Class is based on minimal scripting. so in some cases only one or two lines of code are necessary to perform a database action. if you want write your own queries you can disable Active Record Class in your database config file.
The following functions are used to build SELECT statements.
get_where() was formerly known as getwhere(), which has been removed from lastest version of CodeIgniter.
If we are selecting all (*) from a table we do not need to use this function.
As shown above, the FROM portion of our query can be specified in the $this->db->get() function.
Now we use multiple function calls.
This function used to generate LIKE clauses, which is useful for doing searches.
With the help of this function we can set limit of rows return by query.
The following functions are used to build INSERT statements.
This function used to generates an update string and runs the query based on the data you supply.
This Function is uesd to generates a delete SQL string and runs the query.