Select a column where the values of the given columns are null
@param string $columns
@param boolean $logicalAnd Indicates whether to use logical AND (TRUE) or OR (FALSE)
@return Table
493432
public function areNull(array $columns, $logicalAnd = true) {
        foreach ($columns as $column) {
            $this->isNull($column, $logicalAnd);
        }
        return $this;
    }
128005
public function select($columns, $option = null)
    {
        $this
            ->getQueryBuilder()
            ->select($columns, $option);

        return $this;
    }
1007080
public function executeSelect($tableName, $columns = '*', $where = null, $afterWhere = '')
    {
        list($where, $params) = $this->_buildWhere($where);
        $query = "SELECT $columns FROM $tableName $where $afterWhere";
        if (!($stmt = $this->prepare($query))) {
            return false;
        }
        $stmt->execute($params);
        return $stmt;
    }
1280662
public function select_array(array $columns, $reset = false)
	{
		$this->_select = $reset ? $columns : array_merge($this->_select, $columns);

		return $this;
	}
406389
public function select($columns = "")
    {
        //check if columns were passed as individual string parameters

        if (func_num_args() > 1) {
            $this->columns = $this->columnize(func_get_args());
        } else {
            //check if a simgle array of columns was passed(a hack)
            $this->columns = is_array($columns) ? $this->columnize($columns)
                : self::sanitize($columns);
        }

        return $this;
    }
483162
public function selectValue($tableName, $column, $where = null)
    {
        $stmt = $this->executeSelect($tableName, $column, $where);
        return $stmt->fetchColumn();
    }
1150942
public SelectBuilder columns(String... columns) {
    for (String column : columns) {
      column(column, null);
    }

    return this;
  }
290081
public function selectModelColumns(iterable $columns = null): self
    {
        if ($columns !== null) {
            $quotedColumns = [];
            foreach ($columns as $column) {
                $quotedColumns[] = $this->quoteDoubleIdentifier($this->getAlias(), $column);
            }
        } else {
            $quotedColumns = $this->getModelColumns();
        }

        $this->select($quotedColumns);

        return $this;
    }
1013542
public function addSelectColumns(array $columns)
    {
        foreach ($columns as $column) {
            is_array($column)
                ? count($column) != count($column, true)
                ? $this->addSelectColumns(...$column) : $this->addSelectColumn(...$column) : $this->addSelectColumn($column);
        }
        
        return $this;
    }
595622
public function findBy($column, $value, array $columns = ['*'])
    {
        return $this->where([$column => $value], '=', null, 'and', $columns)->first();
    }
1137448
public function startGroup($logicalAnd = true) {
        if ($this->where)
                $this->where .= ' ' . ($logicalAnd ? 'AND' : 'OR') . ' (';
        else $this->where = ' WHERE (';

        return $this;
    }
884302
public function columns($columns = '*')
    {
        if (false === is_array($columns) && $columns != '*') {
            $columns = func_get_args();
        }
        foreach ($columns as $column) {
            $this->sql['columns'][$column] = 1;
        }
        return $this;
    }
60908
private function validateTableAndCol ($table, $columns) {
        if (!$this->isValidTable($table)) {
            return false;
        }
        
        foreach ($columns as $column) {
            if (!$this->isValidColumn($table, $column)) {
                return false;
            }
        }

        return true;
    }
1047658
protected function _addSelect(array $columns) {
		if(array_values($columns) === $columns) {
			foreach($columns as $k=>$v) {
				unset($columns[$k]);
				$columns[$v] = $v;
			}
		}
		$this->columns = array_merge($this->columns, $columns);
		return $this;
	}
1311740
public function where($column, $operator = '=', $value = null, $boolean = 'and', array $columns = ['*'])
    {
        return $this->mediator->transform($this->mediator(func_get_args()));
    }
181718
public function tableColumns($tableColumns = null)
    {
        if ($tableColumns === null)
        {
            return $this->_tableColumns;
        }
        $this->_tableColumns = $tableColumns;

        return $this;
    }
605070
public function select($columns = null)
	{
		$columns = func_get_args();

		$this->_select = array_merge($this->_select, $columns);

		return $this;
	}