The implementation method of PHP class coherence operation

The consistent operation in PHP looks really cool, it's very handy for code reading, of course, it has to be used in OOP, and in a procedural process, there's no need to use this method. There are useful _call to implement this method, and I write the following example, it is not used _call, we can expand it.

The following write this SQL statement combination class, is mainly used for learning, if there are students want to take to use, please perfect again.

123456789101112131415161718192021222324252627282930313233343536373839

/* * SQL statement combination instance class, originating article Web development Note * www.chhua.com * Learning, non-professional class * */class sql{private $sql =arr Ay ("from" and "" "," where "=" "," order "=" "", "limit" = ""); Public function from ($tableName) {$this->sql[' from ']= ' from '. $tableName; return $this;} Public function where ($_where= ' 1=1 ') {$this->sql["where"]= "where". $_where;return $this;} Public Function order ($_order= ' ID DESC ') {$this->sql["order"]= "ORDER by". $_order;return $this;} Public function limit ($_limit= ') {$this->sql["limit"]= "Limit 0,". $_limit;return $this;} Public Function Select ($_select= ' * ') {return "select". $_select. " ". (Implode ("", $this->sql));}} $sql =new SQL (); echo $sql->from ("TestTable")->where ("Id=1")->order ("id DESC")->limit ()->select ();//Output SELECT * From TestTable WHERE id=1 ORDER by id DESC LIMIT 0,10

