ThinkPHP5.1的数据库链接和增删改查

一、数据库的链接方式

<?php
namespace app\index\controller;
use think\Db;

class Demo
{
//1、全局配置 config/database.php配置
public function dbTest()
{
return Db::table('pzq_article')
->where('id','29')
->value('title');
}

//2、动态配置 think\db\Query.php中有一个方法connect()
public function dbTest2()
{
return Db::connect([
'type'=>'mysql',
'hostname'=>'localhost',
'database'=>'top789',
'username'=>'root',
'password'=>'root',
])
->table('pzq_article')
->where('id','76')
->value('title');
}

//3、DSN连接
public function dbTest3()
{
$dsn = 'mysql://root:root@localhost:3306/top789#utf8';
return Db::connect($dsn)
->table('pzq_article')
->where('id','88')
->value('title');
}

//4、单条查旬
public function dbTest4()
{
$res = Db::table('pzq_article')
->field(['title'=>'标题','id'=>'编号'])//可添加别名
->where('id','=',20)//如果是等号，=可以省略
->find();//如果是主键查询，可省略上面where,这行写->find(20);
dump(is_null($res)?'没有查到':$res);
}
//5、多条查旬
public function dbTest5()
{
$res = Db::table('pzq_article')
->field(['id','cat_id','title'])
->where([
['id','>',20],
['cat_id','=',2],
])//一个条件，直接用表达式->where('id','>',20)。多个条件用数组
->order('id desc')->limit(3)->select();

if(empty($res)){
return '没有查到';
}else{
dump($res);
}

}

//6、数据添加
public function dbTest6()
{
$data = [
'name'=>'Sam2',
'age'=>'29',
'posttime'=>time()
];
$dataall=[
['name'=>'Sam3','age'=>'29','posttime'=>time()],
['name'=>'Sam4','age'=>'30','posttime'=>time()],
];
//(1)单条插入
//return Db::table('test')->data($data)->insert();
//(2)插入同时返回新增主键id
//return Db::table('test')->insertGetId($data);
//(3)插入多条数据
return Db::table('test')->data($dataall)->insertAll();
}
//更新数据
public function dbTest7()
{
// return Db::table('test')
// ->where('id','=',4)
// ->update(['name'=>'SamC','age'=>'31']);
//如果where条件是主键，还可以如下使用
return Db::table('test')
->update(['name'=>'SamCheng','age'=>'30','id'=>4]);
}
//删除操作
public function dbTest8()
{
//return Db::table('test')->delete(6);
//或者
return Db::table('test')->where('id',5)->delete();
}
//mysql原生语句 查询
public function dbTest9()
{
$sql = "select name,age from test where id>2";
dump(Db::query($sql));
}
//mysql 增、删、改 用Db::execute($sql)
public function dbTest10()
{
//$sql = "update test set name='samC' where id=4";
//$sql = "insert test set name='Yan',age='30'";
$sql = "delete from test where id=4";
return Db::execute($sql);
}

}