Test existence of row field

@param  string $columnName The column key.
@return boolean
486630
public function __isset($columnName) {
        // Check if native column from database.
        $result = parent::__isset($columnName);
        if (!$result) {
            // Check if "virtual" column added thru Garp modification.
            $result = array_key_exists($columnName, $this->_related) ||
                array_key_exists($columnName, $this->_virtual);
        }
        return $result;
    }
388666
public function hasRow($rowKey) : bool
    {
        $this->validateRowKey(__METHOD__, $rowKey);
        $this->loadRows();

        $rowHash = ValueHasher::hash($rowKey);

        return isset($this->rows[$rowHash]);
    }
892513
public static function tableExists($tableName)
    {
        $query = "SELECT 1 FROM $tableName LIMIT 1";

        try {
            $result = Connection::db()->query($query);
        } catch (Exception $e) {
            return false;
        }

        return $result !== false;
    }
51670
public function getColumnResult(string $columnName): FieldSearchResult
    {
        if (!$this->hasColumnResult($columnName)) {
            throw new \RuntimeException('Could not find changed column named "' . $columnName . '"');
        }

        return $this->fieldMatchList[$columnName];
    }
1321389
private function getField($fieldname)
    {
        if (array_key_exists($fieldname, $this->colmodel)) {
            return $this->colmodel[$fieldname];
        } else {
            return false;
        }
    }
357965
private function getFieldNameForColumn($tableName, $columnName, $fk = false)
    {
        if (isset($this->fieldNamesForColumns[$tableName], $this->fieldNamesForColumns[$tableName][$columnName])) {
            return $this->fieldNamesForColumns[$tableName][$columnName];
        }

        $columnName = strtolower($columnName);

        // Replace _id if it is a foreignkey column
        if ($fk) {
            $columnName = str_replace('_id', '', $columnName);
        }

        return Inflector::camelize($columnName);
    }
361753
public boolean isInsertableColumn(final String columnName)
   {
      // Use index iteration to avoid generating an Iterator as side-effect
      final FieldColumnInfo[] fcInfos = getInsertableFcInfos();
      for (int i = 0; i < fcInfos.length; i++) {
        if (fcInfos[i].getCaseSensitiveColumnName().equals(columnName)) {
           return true;
        }
      }
      return false;
   }
653637
public function hasField($tableName, $fieldName)
    {
        if (!$this->hasTable($tableName)) {
            return false;
        }
        $fields = $this->fieldList($tableName);
        return array_key_exists($fieldName, $fields);
    }
490681
public function __isset($columnName)
    {
        $columnName = $this->_transformColumn($columnName);
        return array_key_exists($columnName, $this->_data);
    }
1058010
public function getColumnByName(string $columnName) : BufferedSQLResultColumn {
		if (\array_key_exists($columnName, $this->columns)) {
			return $this->columns[$columnName];
		} else {
			throw new \OutOfBoundsException('Column ' . $columnName . ' does not exist in SQL result');
		}
	}
698098
public function getRowByValue ($columnName, $value)
		{
			$query = $this->database->createQuery()
				->whereEqual($columnName, $value)
				->limit(1);

			return $this->getRows($query)
				->fetchRow();
		}
809956
public function isFieldIndexed($fieldName)
    {
        $indexes = $this->getIndexInfo();
        foreach ($indexes as $index) {
            if (isset($index['key']) && isset($index['key'][$fieldName])) {
                return true;
            }
        }
        return false;
    }
783725
public function existDatabase(string $dbName): bool
    {
        $sql = 'SELECT SCHEMA_NAME
            FROM INFORMATION_SCHEMA.SCHEMATA
            WHERE SCHEMA_NAME = %s;';

        $sql = sprintf($sql, $this->quoter->quoteValue($dbName));
        $row = $this->db->query($sql)->fetch(PDO::FETCH_ASSOC);

        return !empty($row['SCHEMA_NAME']);
    }
754406
public function getFieldInformation($tableName, $fieldName)
    {
        $columns = $this->database->metaColumns($tableName);

        foreach($columns as $column) {
            if ($column->name === $fieldName) {

                return $column;
            }
        }

        return null;
    }
574039
public function hasTable($tableName)
    {
        $dbMetadata = Source\Factory::createSourceFromAdapter($this->db);
        $tableNames = $dbMetadata->getTableNames();

        return in_array($tableName, $tableNames);
    }
235467
public function get_column_data($columnname) {
        $this->setup();
        $this->currpage = 0;
        $this->query_db($this->tablemaxrows);
        $result = array();
        foreach ($this->rawdata as $row) {
            $result[] = $row->$columnname;
        }
        return $result;
    }
1321993
protected static function checkColumn($tableName, $columnName, $con=NULL)
    {
        $connection = self::checkConnection($con);

            $result = $connection->prepare("SELECT {$columnName} FROM {$tableName}");
            $result->execute();
            if (! $result->columnCount())
            {
                throw new ColumnNotExistExeption();
            }
            return $columnName;
    }