Question

thinkphp 怎么实现对mysql做到创建表，修改字段，添加字段，删除字段

Answer 1

<?php
class MysqlManage{
/*创建数据库，并且主键是aid
* table 要查询的表名
*/
function createTable($table){
$sql="CREATE TABLE IF NOT EXISTS `$table` (`aid` INT NOT NULL primary key)ENGINE = InnoDB;";
M()->execute($sql);
$this->checkTable($table);
}
/*
* 检测表是否存在，也可以获取表中所有字段的信息
* table 要查询的表名
* return 表里所有字段的信息
*/
function checkTable($table){
$sql="desc `$table`";
$info=M()->execute($sql);
return $info;
}

/*
* 检测字段是否存在，也可以获取字段信息(只能是一个字段)
* table 表名
* field 字段名
*/
function checkField($table,$field){
$sql='desc `$table` $field';
$info=M()->execute($sql);
return $info;
}

/*
* 添加字段
* table 表名
* info 字段信息数组 array
* return 字段信息 array
*/
function addField($table,$info){
$sql="alter table `$table` add column";
$sql.=$this->filterFieldInfo();
M()->execute($sql);
$this->checkField($table,$info['name']);
}

/*
* 修改字段
* 不能修改字段名称，只能修改
*/
function editField($table,$info){
$sql="alter table `$table` modify ";
$sql.=$this->filterFieldInfo($info);
M()->execute($sql);
$this->checkField($table,$info['name']);
}

/*
* 字段信息数组处理，供添加更新字段时候使用
* info[name] 字段名称
* info[type] 字段类型
* info[length] 字段长度
* info[isNull] 是否为空
* info['default'] 字段默认值
* info['comment'] 字段备注
*/
private function filterFieldInfo($info){
if(!is_array($info))
return
$newInfo=array();
$newInfo['name']=$info['name'];
$newInfo['type']=$info['type'];
switch($info['type']){
case 'varchar':
case 'char':
$newInfo['length']=empty($info['length'])?100:$info['length'];
$newInfo['isNull']=$info['isNull']==1?'NULL':'NOT NULL';
$newInfo['default']=empty($info['default'])?'':'DEFAULT '.$info['default'];
$newInfo['comment']=empty($info['comment'])?'':'COMMENT '.$info['comment'];
break;
case 'int':
$newInfo['length']=empty($info['length'])?7:$info['length'];
$newInfo['isNull']=$info['isNull']==1?'NULL':'NOT NULL';
$newInfo['default']=empty($info['default'])?'':'DEFAULT '.$info['default'];
$newInfo['comment']=empty($info['comment'])?'':'COMMENT '.$info['comment'];
break;
case 'text':
$newInfo['length']='';
$newInfo['isNull']=$info['isNull']==1?'NULL':'NOT NULL';
$newInfo['default']='';
$newInfo['comment']=empty($info['comment'])?'':'COMMENT '.$info['comment'];
break;
}
$sql=$newInfo['name']." ".$newInfo['type'];
$sql.=(!empty($newInfo['length']))?($newInfo['length']) .' ':' ';
$sql.=$newInfo['isNull'].' ';
$sql.=$newInfo['default'];
$sql.=$newInfo['comment'];
return $sql;
}

/*
* 删除字段
* 如果返回了字段信息则说明删除失败，返回false，则为删除成功
*/
function dropField($table,$field){
$sql="alter table `$table` drop column $field";
M()->execute($sql);
$this->checkField($table,$filed);
}

/*
* 获取指定表中指定字段的信息(多字段)
*/
function getFieldInfo($table,$field){
$info=array();
if(is_string($field)){
$this->checkField($table,$field);
}else{
foreach($field as $v){
$info[$v]=$this->checkField($table,$v);
}
}
return $info;
}
}