Need case-insensitive checks for dupes in the $options['indexes'] array

I don't think this is a good change. You should instead fix it by identifying why you have 2 indexes with the same name, instead of this hack.

I'll try to debug why there were two indexes named employeecode and employeeCode. I think there's a bug somewhere in the MySQL drivers where the case-conversions failed.

Had no time yesterday as I was focused more on getting my work done than actually fixing the problem

If you do this in the base model, note the capital C in the employeeCode index:

$this->hasColumn('employeeCode', 'string', 11);
$this->index('employeeCode', array('fields' => array('employeeCode')));

It will result in this SQL statement for the table creation:

CREATE TABLE employees (id BIGINT AUTO_INCREMENT, employeecode VARCHAR(11), first VARCHAR(50), last VARCHAR(50), created_at DATETIME NOT NULL, updated_at DATETIME NOT NULL, INDEX employeeCode_idx (employeecode), INDEX employeecode_idx (employeecode), PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE = INNODB

Note that it tries to create 2 indexes named employeeCode_idx and employeecode_idx.

If I change the declaration to $this->index('employeecode', array('fields' => array('employeeCode')));, then it works:

CREATE TABLE employees (id BIGINT AUTO_INCREMENT, first VARCHAR(50), last VARCHAR(50), employeecode VARCHAR(11), created_at DATETIME NOT NULL, updated_at DATETIME NOT NULL, INDEX employeecode_idx (employeecode), PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE = INNODB

Still not sure what the cause is. I'm not too familiar with the flow of the Export Drivers yet.

I see, I think we have some problems when you have columns which are camel case. I would recommend using underscores to avoid any issues until this can be resolved.