protected function extractPrimaryKey()
    {
        if (static::$factories[$this->table]['primary_key'] !== null) {
            return static::$factories[$this->table]['primary_key'];
        }

        if (preg_match('/^chado\./', $this->table)) {
            $schema = chado_get_schema(str_replace('chado.', '', $this->table));
            if ($schema) {
                if (isset($schema['primary key'])) {
                    return $schema['primary key'][0];
                } elseif (isset($schema['primary keys'])) {
                    return $schema['primary keys'][0];
                }
            }
        }

        throw new \Exception("Unable to determine primary key for $this->table factory. Please provide the primary key such as `nid` as a third argument in Factory::define().");
    }
protected function extractPrimaryKey()
    {
        if (static::$factories[$this->table]['primary_key'] !== null) {
            return static::$factories[$this->table]['primary_key'];
        }

        if (preg_match('/^chado\./', $this->table)) {
            $schema = chado_get_schema(str_replace('chado.', '', $this->table));
            if ($schema) {
                if (isset($schema['primary key'])) {
                    return $schema['primary key'][0];
                } elseif (isset($schema['primary keys'])) {
                    return $schema['primary keys'][0];
                }
            }
        }

        throw new \Exception("Unable to determine primary key for $this->table factory. Please provide the primary key such as `nid` as a third argument in Factory::define().");
    }
protected function extractPrimaryKey ( ) { if ( static :: $ factories [ $ this -> table ] [ 'primary_key' ] !== null ) { return static :: $ factories [ $ this -> table ] [ 'primary_key' ] ; } if ( preg_match ( '/^chado\./' , $ this -> table ) ) { $ schema = chado_get_schema ( str_replace ( 'chado.' , '' , $ this -> table ) ) ; if ( $ schema ) { if ( isset ( $ schema [ 'primary key' ] ) ) { return $ schema [ 'primary key' ] [ 0 ] ; } elseif ( isset ( $ schema [ 'primary keys' ] ) ) { return $ schema [ 'primary keys' ] [ 0 ] ; } } } throw new \ Exception ( "Unable to determine primary key for $this->table factory. Please provide the primary key such as `nid` as a third argument in Factory::define()." ) ; }
Get the primary key of a table.

@throws \Exception
@return string
Get the primary key of a table .