what does fourth parameter ($escape) actually do for $builder->like?

I was expecting that the fourth parameter for the Builder::like function would cause special characters in the $match parameter to be escaped. I was quite surprised to see that supplying FALSE for this parameter results in no quotation marks for the $match parameter. Is this a bug?

An example. I would expect the % in 'H%' to be escaped:

PHP Code:

    function test2() {
        $db = \Config\Database::connect("tests");
        $builder = $db->table("my_table");
        $builder->like('col1', '20%', 'none', false);
        die($builder->testMode()->getCompiledSelect());
    } 


The output of this function is:

Code:

SELECT * FROM `db_my_table` WHERE col1 LIKE 20%

whereas I was expecting an $escape of false to suppress escaping of special characters, perhaps yielding something like this:

Code:

SELECT * FROM `db_my_table` WHERE col1 LIKE '20%'

whereas an $escape value of true

PHP Code:

        $builder->like('col1', '20%', 'none', true); 


yields this:

Code:

SELECT * FROM `db_my_table` WHERE `col1` LIKE '20%' ESCAPE '!'

when I thought it would escape the special wildcard char % like so:

Code:

SELECT * FROM `db_my_table` WHERE col1 LIKE '20!%' ESCAPE '!'

NOTE that in every case the table is surrounded by backticks, and the $escape parameter turns on/off the backticks around the column name and the quotes around the pattern to be matched.

Can someone explain to me what the $escape parameter is really doing? The documentation is not very clear at all:

$escape (bool) – Whether to escape values and identifiers

In CI3,

PHP Code:

$this->db->like('col1', '20%', 'none', false);
$sql = $this->db->get_compiled_select("my_table"); 


Code:

SELECT *
FROM `my_table`
WHERE  col1  LIKE '20%'

At least, the following SQL is invalid, and it must be a bug in CI4.

Code:

SELECT * FROM `db_my_table` WHERE col1 LIKE 20%

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