About Yii model query based on array and object

This article mainly introduces Yii's Model query techniques based on arrays and objects. It analyzes Yii's Model query techniques for arrays and objects in detail based on the example form. Friends in need can refer to it

The examples in this article describe Yii's array- and object-based Model query techniques. Share it with everyone for your reference, the details are as follows:

For a Model Post, there are the following 4 query methods, which return objects or object arrays.

//查找满足指定条件的结果中的第一行 find the first row satisfying the specified condition
$post=Post::model()->find($condition,$params);
//查找具有指定主键值的那一行 find the row with the specified primary key
$post=Post::model()->findByPk($postID,$condition,$params);
//查找具有指定属性值的行 find the row with the specified attribute values
$post=Post::model()->findByAttributes($attributes,$condition,$params);//未找到返回null
//通过指定的SQL 语句查找结果中的第一行 find the first row using the specified SQL statement
$post=Post::model()->findBySql($sql,$params);

If the find method finds a row that meets the query conditions, it will return a Post instance whose attributes contain the values ​​of the corresponding columns in the data table row. Then we can read the loaded value like a normal object property, such as echo $post->title;. The find method will return null if nothing is found in the database using the given query criteria.

When calling find, we use $condition and $params to specify the query conditions. Here $condition can be a WHERE string in the SQL statement and $params is an array of parameters whose values ​​should be bound to the placeholders in $condation. For example: Suppose we query the data with postID = 10

// find the row with postID=10
$post=Post::model()->find('postID=:postID', array(':postID'=>10));

The condition $condition is the where part of our sql. What about the parameters? They are passed through params, but the name is added with ":".

YII has a CDbCriteria class to construct queries. If we query the title with a postId of 10, CdbCriteria is constructed like this

$criteria=new CDbCriteria;
$criteria->select='title'; // only select the 'title' column
$criteria->condition='postID=:postID';
$criteria->params=array(':postID'=>10);
$post=Post::model()->find($criteria); // $params is not needed

An alternative to CDbCriteria is to pass an array to the find method. The keys and values ​​of the array respectively correspond to the attribute names and values ​​of the criterion. The above example can be rewritten as follows:

$post=Post::model()->find(array(
  'select'=>'title',
  'condition'=>'postID=:postID',
  'params'=>array(':postID'=>10),
));

Of course it also applies to findAll()

self::$_items[$type]=array();
$models=self::model()->findAll(array(
  'condition'=>'type=:type',
  'params'=>array(':type'=>$type),
  'order'=>'position',
));

when a query condition When it comes to matching several columns by specified values, we can use findByAttributes(). We make the $attributes parameter an array of values ​​indexed by column name.
$attributes in findByAttributes is the name of the field. How to query if the title is abc? See below

Post::model()->findByAttributes(array('title'=>'abc'))

Other methods:

1. $admin=Admin::model()->findAll($condition,$params);

This method is to query a collection based on a condition, such as:

findAll("username=:name",array(":name"=>$username));

2, $admin=Admin::model()->findAllByPk($postIDs, $condition,$params);
findAllByPk($id,"name like ':name' and age=:age" ,array(':name'=>$name,'age'=> $age));
This method queries a collection based on the primary key. Multiple primary keys can be used, such as:

findAllByPk(array(1,2));

3, $admin=Admin::model()->findAllByAttributes ($attributes,$condition,$params);

This method is to query a collection based on conditions. It can be multiple conditions. Put the conditions into an array, such as:

findAllByAttributes(array('username'=>'admin'));

4. $admin=Admin::model()->findAllBySql($sql,$params);

This method is to query an array based on the SQL statement, such as:

findAllBySql("select *from admin where username=:name",array(':name'=>'admin'));

2. Method of querying objects

1. $admin=Admin::model()->findByPk($postID,$condition,$ params);

Query an object based on the primary key, such as:

findByPk(1);

2, $row=Admin::model()->find($condition, $params);

Query a set of data based on a condition, there may be multiple, but it only returns the first row of data, such as:

find('username=:name',array(':name'=>'admin'));

3, $admin=Admin::model()->findByAttributes($attributes,$condition,$params);

This method is to query a set of data based on conditions, which can be multiple conditions. The conditions are placed in the array, and the first data he queries is also:

findByAttributes(array('username'=>'admin'));

4, $admin=Admin::model()->findBySql($sql,$params);

This method is to query a set of data based on the SQL statement. It also queries the first piece of data, such as:

findBySql("select *from admin where username=:name",array(':name'=>'admin'));

5. Put together a method to obtain SQL. Query an object based on find

$criteria=new CDbCriteria;
$criteria->select='username'; // only select the 'title' column
$criteria->condition='username=:username';
$criteria->params=array(':username=>'admin');
$post=Post::model()->find($criteria); // $params is not needed

3. Query the number and determine whether the query has results

1, $n=Post: :model()->count($condition,$params);

This method is to query how many records there are in a collection based on a condition and return an int type number, such as

count("username=:name",array(":name"=>$username));

2, $n=Post::model()->countBySql($sql,$params);

This method is to query how many items there are in a collection based on the SQL statement Record, return an int type number, such as

countBySql("select *from admin where username=:name",array(':name'=>'admin'));

3, $exists=Post::model()->exists($condition,$params);
This method It is based on a conditional query to see whether the array obtained has data. If there is data, a true is returned, otherwise it is not found.

4. Adding method

$admin=new Admin;
$admin->username=$username;
$admin->password=$password;
if($admin->save()>0){
  echo "添加成功";
}else{
  echo "添加失败";
}

5. Modification method

1. Post::model()->updateAll($attributes,$condition,$params);

$count = Admin::model()->updateAll(array('username'=>'11111','password'=>'11111'),'password=:pass',array(':pass'=>'1111a1'));
if($count>0){
  echo "修改成功";
}else{
  echo "修改失败";
}

2. Post::model()->updateByPk($pk,$attributes,$condition,$params);

$count = Admin::model()->updateByPk(1,array('username'=>'admin','password'=>'admin'));
$count = Admin::model()->updateByPk(array(1,2),array('username'=>'admin','password'=>'admin'),'username=:name',array(':name'=>'admin'));
if($count>0){
  echo "修改成功";
}else{
  echo "修改失败";
}

$pk代表主键，可以是一个也可以是一个集合，$attributes代表是要修改的字段的集合，$condition代表条件，$params传入的值

3、Post::model()->updateCounters($counters,$condition,$params);

$count =Admin::model()->updateCounters(array('status'=>1),'username=:name',array(':name'=>'admin'));
if($count>0){
  echo "修改成功";
}else{
  echo "修改失败";
}

array('status'=>1)代表数据库中的admin表根据条件username='admin'，查询出的所有结果status字段都自加1

六、删除的方法

1、Post::model()->deleteAll($condition,$params);

$count = Admin::model()->deleteAll('username=:name and password=:pass',array(':name'=>'admin',':pass'=>'admin'));
      $id=1,2,3
      deleteAll('id in(".$id.")');删除id为这些的数据
if($count>0){
  echo "删除成功";
}else{
  echo "删除失败";
}

2、Post::model()->deleteByPk($pk,$condition,$params);

$count = Admin::model()->deleteByPk(1);
$count = Admin::model()->deleteByPk(array(1,2),'username=:name',array(':name'=>'admin'));
if($count>0){
  echo "删除成功";
}else{
  echo "删除失败";
}

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