public function primaryKey(string $columnName)
    {
        $this->primaryKey = $this->buildPrimaryKeyColumn($columnName);
        $this->columns    = [$columnName => $this->primaryKey] + $this->columns;
    }
public function primaryKey(string $columnName)
    {
        $this->primaryKey = $this->buildPrimaryKeyColumn($columnName);
        $this->columns    = [$columnName => $this->primaryKey] + $this->columns;
    }
public function primaryKey ( string $ columnName ) { $ this -> primaryKey = $ this -> buildPrimaryKeyColumn ( $ columnName ) ; $ this -> columns = [ $ columnName => $ this -> primaryKey ] + $ this -> columns ; }
Defines an unmapped primary key column.

@param string $columnName

@return void
Defines an unmapped primary key column .