How to print SQL statement in codeigniter model

问题:

I have a sql statement in my model,

I then say

$query = $this->db->query($sql, array(fields, fields1);

if ($query) {
    return true:
} else {
    echo "failed";
    return false;
}

My query always fails, how do I get php to print the exact sql statement being sent to my database? And display that on my php view, page

回答1:

To display the query string:

$this->db->last_query();    

To display the query result:

print_r($query);

---

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回答2:

You can use this:

$this->db->last_query();

"Returns the last query that was run (the query string, not the result)."

Reff: https://www.codeigniter.com/userguide3/database/helpers.html

回答3:

You can display the ActiveRecord generated SQL:

Before the query runs:

$this->db->_compile_select(); 

And after it has run:

$this->db->last_query(); 

回答4:

if you need a quick test on your query, this works great for me

echo $this->db->last_query(); die;

回答5:

After trying without success to use _compiled_select() or get_compiled_select() I just printed the db object, and you can see the query there in the queries property.

Try it yourself:

var_dump( $this->db );

If you know you have only one query, you can print it directly:

echo $this->db->queries[0];

回答6:

You can simply use this at the end..

echo $this->db->last_query();

回答7:

There is a new public method get_compiled_select that can print the query before running it. _compile_select is now protected therefore can not be used.

echo $this->db->get_compiled_select(); // before $this->db->get();

回答8:

Neither last_query() or get_compiled_select() works for me, so a slight change of pedro's code works for me just fine. Do not include ->get() in your build, this must be before the ->get()

 echo $this->EE->db->_compile_select();

回答9:

I try to @Chumillas's answer and @chhameed's answer, but it not work,because the sql is wrong.So I found new approach,like this:

• Insert echo $sql; flush(); exit; into before return $sql; _compile_select function of DB_active_rec.php

回答10:

Add this line right after the query you want to print.

Example:

$query = $this->db->query('SELECT * FROM table WHERE condition');

//Add this line.

printx($this->db->last_query());

or

echo $this->db->last_query();

回答11:

I had exactly the same problem and found the solution eventually. My query runs like:

$result = mysqli_query($link,'SELECT * FROM clients WHERE ' . $sql_where . ' AND ' . $sql_where2 . ' ORDER BY acconame ASC ');

In order to display the sql command, all I had to do was to create a variable ($resultstring) with the exact same content as my query and then echo it, like this:<?php echo $resultstring = 'SELECT * FROM clients WHERE ' . $sql_where . ' AND ' . $sql_where2 . ' ORDER BY acconame ASC '; ?>

It works!

回答12:

I read all answers here, but cannot get

echo $this->db->get_compiled_select();

to work, It gave me error like,

Call to protected method CI_DB_active_record::_compile_select() from context 'Welcome'in controllers on line xx

So i removed protected from the below line from file \system\database\DB_active_rec.php and it worked

protected function _compile_select($select_override = FALSE)

回答13:

use get_compiled_select() to retrieve query instead of replace it