What is graceful programming? What is an elegant code?

Personal Understanding: The so-called elegant programming is to drink coffee, touch the keyboard, thinking about business; The elegant code is defined as: 1, as far as possible less single double quotation marks; 2, do not nest; 3, the name is all the most basic English words; 4, the code, like English, is a paragraph; 5, an application code organization clear, preferably a tree relationship, network relationship is less useful. Below is a coherent operation of SQL query implementation method, please guide the guidance! /** * DB coherent operation, SQL conditional construction * from:eqphp FrameWork * Author:art_youth * e-mail:258122391@qq.com * Pub data:2012-11-09 */ Class query{ Public $sql = '; Public $option =array (); Static $keyword =array (' select ', ' from ', ' where ', ' group ', ' have ', ' order ', ' limit '); Initializing query parameters function __construct ($table, $prefix = ") { $this->option[' from ']= $prefix. $table; } Construction parameters function __call ($method, $param) { if (In_array ($method, Self:: $keyword)) { $this->option[$method]= $param [0]; return $this; } } Output query Results function out ($mode = ' sql ', $rs _count=0, $now _page=1, $page _size=20) { $this->sql= '; foreach (self:: $keyword as $key) { $value = ($key = = ' Group ' | | $key = = ' order ')? $key. ' By ': $key; if ($key = = = ' WHERE ' && is_array ($this->option[' where ')) { $this->option[' where ']=self::condition ($this->option[' where '); } if (Isset ($this->option[$key]) && trim ($this->option[$key])) { $this->sql.= '. $value. ' '. Trim ($this->option[$key]); } unset ($this->option[$key]); } $this->sql=trim ($this->sql); Switch ($mode) { Case ' RS ': Return Db::rs ($this->sql); Case ' list ': Return Db::rs_list ($this->sql); Case ' page ': Return DB::p age_list ($this->sql, $rs _count, $now _page, $page _size); Default return $this->sql; } } Constructing SQL query criteria static function condition ($data) { Working with logical connectors $logic = ' and '; if (Isset ($data [' logic ')]) { $logic = '. $data [' logic ']. ' '; unset ($data [' logic ']); } Working with strings (native SQL) if (Isset ($data [' query '])) { $condition []= ' ('. $data [' query ']. ') '; unset ($data [' query ']); } Processing condition data foreach ($data as $key = = $value) { $condition []= ' ('. Self::p arse_expression ($key, $value). ') '; } Return implode ($logic, $condition); } Parsing an expression private static function Parse_expression ($key, $value) { if (Is_numeric ($value)) return $key. ' = '. $value; if (is_string ($value)) return $key. ' = "'. $value. '"; if (Is_array ($value)) { Basic condition Query if (Preg_match ('/^ (eq|neq|gt|egt|lt|elt) $/i ', $value [0])) { Is_string ($value [1]) && $value [1]= ' "". $value [1]. ' "'; $operator =array (' eq ' = ' = ', ' neq ' = ' <> ', ' gt ' = ' > ', ' egt ' = ' >= ', ' lt ' = ' < ', ' elt ' = ' <= ',); return $key. $operator [$value [0]]. $value [1]; } In range Lookup if (In_array ($value [0],array (' in ', ' not ')}) { Is_array ($value [1]) && $value [1]=implode (', ', $value [1]); return $key. ' '. $value [0]. ' ('. $value [1]. ') '; } Between interval search if (In_array ($value [0],array (' between ', ' not between ')) { $param =is_string ($value [1])? Explode (', ', $value [1]): $value [1]; return $key. ' '. $value [0]. ' '. $param [0]. ' and '. $param [1]; } Like fuzzy matching if (In_array ($value [0],array (' like ', ' Don't like ')}) { if (Is_array ($value [1])) { $buffer =array (); foreach ($value [1] as $param) { $buffer []= $key. ' '. $value [0]. ' "'. $param. '"; } $logic =isset ($value [2])? ". $value [2]. ' ': ' or '; Return implode ($logic, $buffer); } if (Strpos ($key, ' | ')!== false) { $buffer =array (); foreach (Explode (' | ', $key) as $field) { $buffer []= ' ('. $field. ') '. $value [0]. ' "'. $value [1]. ') '; } Return implode (' or ', $buffer); } if (Strpos ($key, ' & ')!== false) { $buffer =array (); foreach (Explode (' & ', $key) as $field) { $buffer []= ' ('. $field. ') '. $value [0]. ' "'. $value [1]. ') '; } Return implode (' and ', $buffer); } return $key. ' '. $value [0]. ' "'. $value [1]. '"; } Math interval Query (1,9)/[2,3) if ($value [0] = = = = ' extent ') { $logic =isset ($value [2])? ". $value [2]. ' ': ' && '; $operator =array (' = ' (' = ' > ', ' [' = ' = ' >= ', ') ' = ' < ', '] ' and ' = ' <= '); Preg_match ('/^ (\ (|\[) (. *), (. *) (\) |\]) $/', $value [1], $param); $result = "; Isset ($param [2]) && $result. = $key. $operator [$param [1]]. $param [2]; Isset ($param [4]) && $result. = $logic. $key. $operator [$param [4]]. $param [3]; return $result; } Return '; } } Resource Recycling function __destruct () { Unset ($this->option, $this->sql); } } Copy Code

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