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PHP+Mysql实现多关键字与多字段生成SQL语句的函数,mysqlsql
php+mysql怎实现无限级别分类,数据库怎设计?一条SQL语句读出数据然后生成数组
mysql中的sql语句存在关键字怎办
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PHP+Mysql实现多关键字与多字段生成SQL语句的函数,mysqlsql

Jun 13, 2016 am 09:22 AM
mysql php sql statement

PHP+Mysql实现多关键字与多字段生成SQL语句的函数,mysqlsql

本文实例讲述了PHP+Mysql实现多关键字与多字段生成SQL语句的函数的方法。分享给大家供大家参考。具体实现方法如下:

先看实例:

复制代码 代码如下:

$keyword="1 2 3";
echo $sql=search($keyword,"enter_gongyin_pic","a+b+c"); //函数生成,没有LIMIT,没有ORDER BY


生成:

复制代码 代码如下:

SELECT * FROM `enter_gongyin_pic` WHERE `a` LIKE '%1%' OR `a` LIKE '%2%' OR `a` LIKE '%3%' OR `b` LIKE '%1%' OR `b` LIKE '%2%' OR `b` LIKE '%3%' OR `c` LIKE '%1%' OR `c` LIKE '%2%' OR `c` LIKE '%3%'


$keyword由POST或者GET获得.按空格分开 可以多字段去查找.

实现函数如下:

复制代码 代码如下:

function search($keyword,$table,$field) 

//======================================================== 
 
//形参说明: 
//keyword为关键字,如“北京首都 方向 火车”。带有空格或者不带 
//table为表名,如enter_gongyin_pic。 
//field为字段组合,如查找一个字段就写好 name  
//如查找两个以上就用 name+picdir 
//======================================================== 
//首先确定field 
$new_field=explode("+",$field); //按+剥离 
$field_count=count($new_field); //得到的结果数量 
 
 
$newstring=explode(" ",$keyword); //按空格剥离 
$newstring2=array(); 
   //把字符串去掉没有用的空格叔祖元素 
   $i=0; 
   foreach ($newstring as $key => $value) { 
   if($value!="") 
   { 
   $newstring2[$i]=$value; 
   $i++; 
   } 
   } 
//把字符串去掉没有用的空格叔祖元素, 
         
$result_count=count($newstring2); //得到的结果数量 
 
//下面生成SQL语句 
 
 
//********************** if($field_count==1) //找1个字段 START **************************** 
if($field_count==1) //找1个字段 

if($result_count==1) //判断如果是一个关键段 
   { 
   $newstring_search=$newstring2[0]; 
$sql="SELECT *  
FROM `$table`  
WHERE `".$new_field[0]."` LIKE '%$newstring_search%'"; 
   } 
      
   if($result_count>1) //判断如果是多个关键段 
   { 
 
$sql="SELECT *  
FROM `$table`  
WHERE "; 
$sql_add=""; 
foreach ($newstring2 as $key => $value) 

  if($key==0) 
   { 
   $sql_add=$sql_add."`".$new_field[0]."` LIKE '%".$value."%'"; 
   } 
   else 
   { 
   $sql_add=$sql_add." OR `".$new_field[0]."` LIKE '%".$value."%'"; 
     
        } 
         
          } 
   
$sql=$sql.$sql_add; 

 

 
//********************** if($field_count==1) //找1个字段 END **************************** 
 
 
//********************** if($field_count>1) //找多个字段 START **************************** 
if($field_count>1) //找多个字段,这个时候$new_field是一个数组。拥有多个字段 

if($result_count==1) //判断如果是一个关键段 

        $newstring_search=$newstring2[0]; //$newstring_search是关键字 
        $sql="SELECT *  
        FROM `$table`  
        WHERE "; 
        $sql_add="";//新增加字段 
        foreach ($new_field as $key => $value) 
        { 
                        if($key==0) 
                        { 
                        $sql_add=$sql_add."`".$value."` LIKE '%".$newstring_search."%'"; 
                        } 
                        else 
                        { 
                        $sql_add=$sql_add." OR `".$value."` LIKE '%".$newstring_search."%'"; 
                        } 
        } 
        $sql=$sql.$sql_add; 

if($result_count>1) //判断如果是多个关键段(多个关键字)========================== 

$sql="SELECT *  
FROM `$table`  
WHERE "; 
$sql_add="";//新增加字段 
foreach ($new_field as $key => $value) 

  if($key==0) //遇到$new_field[0]时候 例:`a` LIKE '%1%' OR `a` LIKE '%2%' OR `a` LIKE '%3%' 
   { //嵌套foreach 
     foreach ($newstring2 as $key2 => $value2) 
      { 
                  if($key2==0) 
                   { 
                        $sql_add=$sql_add."`".$value."` LIKE '%".$value2."%'"; 
                   } 
                   else 
                   { 
                   $sql_add=$sql_add." OR `".$value."` LIKE '%".$value2."%'"; 
                   } 
        } 
    //嵌套foreach 
   } 
   else  
   //(如果是多字段的比如查name+picdir表)开始FOREACH连续循环,每次执行ELSE $new_field[1] $new_field[2] $new_field[3]。 
   //对应的值为$value 
  { 
   //嵌套foreach(多字段与多关键字) 
   foreach ($newstring2 as $key2 => $value2) 
      { 
                  if($key2==0) 
                   { 
                        $sql_add=$sql_add." OR `".$value."` LIKE '%".$value2."%'"; 
                   } 
                   else 
                   { 
                   $sql_add=$sql_add." OR `".$value."` LIKE '%".$value2."%'"; 
                   } 
           } 
   //嵌套foreach 
   } 
         
}//foreach ($new_field as $key => $value)结束 
$sql=$sql.$sql_add; 
}//if($result_count>1)结束 
}//if($field_count>1) 结束 
//********************** if($field_count>1) //找多个字段 END **************************** 
return $sql; 
}

希望本文所述对大家的PHP程序设计有所帮助。

php+mysql怎实现无限级别分类,数据库怎设计?一条SQL语句读出数据然后生成数组

你说的无限级别,不是树状无限吧,只是说类别的个数无限,级别只有两级,对吧

一般大类不会很多,可以使用一个字符来表示,例如用A~Z进行编码,A为新闻、B为体育、……

新闻的类别可以设置为字符类型,第一位表示大累,后面的表示小类,例如A001国际新闻、A002国内新闻、B001篮球、……

建立两个表,一个是新闻大类表,两个字段:大类代码、大类名称;另外一个类别表,也是两个字段:类别代码、类别名称

在你的新闻表里面,只使用一个字符类型的类别字段就可以了。

要产生你那样的树状目录输出,起始非常简单,只要你的SQL语句按照类别进行排序就行了,程序检测每一条数据是否和上面的类别相同,以确定前面是显示+还是|,仅此而已。
 

mysql中的sql语句存在关键字怎办

insert into tb_test (`use`) values ('test');

用这个点,就是上边数字键1左边的那个
 

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