如何在带有 Yii 框架的 oracle 11g 中使用 CLOB

Question

I have object in Yii mapped to a table witch contains one CLOB column.

How I can insert with save() method call an ~54k char length string into a row?

Answer 1

Yii has beforeSave() and afterSave() event methods in it's ActiveRecord models. I would use those instead of overriding the save() method. Put all of the necessary Oracle methods in there. Basically: null out the fields in the beforeSave(), then in the afterSave() write the values to the DB with OCIParse(), etc.

Here is a good blog article about it using the Cake PHP framework, which is very similar (MVC with before and after Save methods). You will need to modify this code to work with Yii, obviously, but it should get you on the right track:

http://nik.chankov.net/2008/01/03/cakephp-and-oracle-handling-clob-fields/

The newest version of Yii has a query builder now too, which might be of some help in the afterSave() code you will need to write:

http://www.yiiframework.com/doc/guide/1.1/en/database.query-builder

Good luck!

Answer 2

I work it out just now. I also need to use BLOB in oracle 11g, I want to insert image into oracle table.

I search it all around the net, finally I found a probably solution at enter link description here .

please click it out.

I follow the example #2

<?php
$db = new PDO('odbc:SAMPLE', 'db2inst1', 'ibmdb2');
$stmt = $db->prepare("insert into images (id, contenttype, imagedata) values (?, ?, ?)");
$id = get_new_id(); // some function to allocate a new ID

// assume that we are running as part of a file upload form
// You can find more information in the PHP documentation

$fp = fopen($_FILES['file']['tmp_name'], 'rb');

$stmt->bindParam(1, $id);
$stmt->bindParam(2, $_FILES['file']['type']);
$stmt->bindParam(3, $fp, PDO::PARAM_LOB);

$db->beginTransaction();
$stmt->execute();
$db->commit();
?>

I get the $db by

$db = Yii::app()->db->getPdoInstance() 

instead by

$db = new PDO('odbc:SAMPLE', 'db2inst1', 'ibmdb2');

and other things are all the same.

Good luck!

Answer 3

This has worked for me, but I have little praise, I am starting the adaptation of MySQL to ORACLE. Crazy!!!

It is a beta, if one can improve it will help.

overwrite the __get function in Model.

class Entidad extends \common\myclass\MyActiveRecord {.......

public function __get($name) {

    $columna = $this->getTableSchema()->getColumn($name);
    $current = parent::__get($name); 
    if (isset($columna->dbType) && $columna->dbType=='CLOB') {          
        if (is_string($current)) {
            return $current;
        } 
        else if (is_null($current)) {
            return $current;
        }
        else if ($this->isAttributeChanged($name)) {
            return $this->getAttribute($name);
        }
        else {
            $valor = stream_get_contents($current);   
            $this->setAttribute($name,$valor);
            return $this->getAttribute($name);                
        }
    } else {            
        return $current;
    }

}

.....

}

Answer 4

Our project also had problems with reading and writing to LOB fields when using yii2 and Oracle DB. As a result, at the moment, I came to the decision to write a class overrides some methods of the ActiveRecord class in yii2, and to inherit some models not from the ActiveRecord, but from it. I made it relatively universal, you can take as a basis for your improvements https://github.com/pivasikkost/yii2-improvements/blob/master/models/ActiveRecordOciLob.php .

<?php

namespace app\models\system;

use Yii;
use \yii\db\ActiveRecord;
use \yii\db\Query;

/**
 * ActiveRecordOciLob is the base class for classes representing relational data in terms of objects,
 * that should work correctly with LOB data in Oracle DB. Used Oci8Connection (in my case - neconix\src\Oci8Connection).
 * 
 * Just inherit your gii generated model class not from ActiveRecord, but from this class,
 * set $clob_attributes, $blob_attributes and $dbOciLobName to work.
 * 
 * @property array $clob_attributes an array of attribute names of the form "['name_1', 'name_2', ...]"
 * @property array $blob_attributes an array of attribute names of the form "['name_1', 'name_2', ...]"
 * @property array $primaryKeyOciLob an array of attribute names of the form "['name_1', 'name_2', ...]"
 * @property string $dbOciLobName Oci8Connection name
 * 
 * @author Konstantin Zosimenko <pivasikkost@gmail.com>
 * @since 2.0
 */
class ActiveRecordOciLob extends ActiveRecord
{
    // METHOD 4. Almost completed, it works!
    
    public static $clob_attributes = [];
    public static $blob_attributes = [];
    public static $dbOciLobName;
    public $primaryKeyOciLob; // Not static! for some reason, being static, when saving one descendant of this class from another descendant of this class, this variable is overwritten and takes the wrong value
    
    /** 
     * @inheritdoc
     */
    public function init()
    {
        parent::init();
        $this->primaryKeyOciLob = static::primaryKey();
    }
    
    /**
     * @return \yii\db\Connection the database connection used by this AR class.
     */
    public static function getDbOciLob()
    {
        return static::$dbOciLobName 
                ? Yii::$app->get(static::$dbOciLobName)
                : static::getDb()
        ;
    }
    
    /**
     * Override ActiveRecord afterFind() method to fix LOB data receiveing
     * Maybe it's better to do this in populateRecord() method
     * 
     * @inheritdoc
     */
    public function afterFind ()
    {
        // Get lob fields as string, because standardly ActiveRecord gets them as resource
        $lob_attributes = array_merge(static::$clob_attributes, static::$blob_attributes);
        
        $where = [];
        foreach ($this->primaryKeyOciLob as $attribute) {
            $where[$attribute] = $this->$attribute;
        }

        foreach ($lob_attributes as $lob_attribute) {
            //$this->$lob_attribute = stream_get_contents($this->$lob_attribute); // Does not work, for some reason always returns 1 value if you try to get multiple records
            $this->$lob_attribute = (new Query())
                ->select($lob_attribute)
                ->from(static::tableName())
                ->where($where)
                ->createCommand(static::getDbOciLob())
                ->queryScalar();
            $this->setOldAttribute($lob_attribute, $this->$lob_attribute);
        }
        
        parent::afterFind ();
    }
    
    /**
     * Override ActiveRecord update() method to fix LOB data update
     * 
     * @inheritdoc
     */
    public function update($runValidation = true, $attributeNames = null)
    {   
        if ($runValidation && !$this->validate($attributeNames)) {
            Yii::info('Model not updated due to validation error.', __METHOD__);
            return false;
        }
        
        if (!$this->beforeSave(false)) {
            return false;
        }
        
        $db = static::getDbOciLob()->getDbh();
        $fields_blob = static::$blob_attributes;
        $fields_clob = static::$clob_attributes; // array with the fields to be updated
        $fields_dirty = $this->getDirtyAttributes($attributeNames); // changed fields with values
        $exist_fields_dirty_clob = array_values(
                array_intersect(array_keys($fields_dirty), $fields_clob)
        );

        
        if (empty($fields_dirty)) {
            $this->afterSave(false, $fields_dirty);
            return 0;
        }
        
        $set = [];
        $into = [];
        foreach ($fields_dirty as $name => $value) {
            if (in_array($name, $fields_clob)) {
                $set[] = $name . " = EMPTY_CLOB()";
                $into[] = ":" . $name;
            /*} elseif (in_array($name, $fields_blob)) {
                $set[] = $name . " = EMPTY_BLOB()";
                $into[] = ":" . $name;*/
            } else {
                $set[] = $name . " = :" . $name;
            }
        }
        $set_stmt = implode(", ", $set); // array to string to fill 'set' clause in the sql
        $where = [];
        foreach ($this->primaryKeyOciLob as $attribute) {
            $where[] = $attribute . "=" .$this->$attribute;
        }
        $where_stmt = implode(" AND ", $where);
        //$returning = implode(", ", array_merge($fields_clob, $fields_blob));
        $returning = implode(", ", $exist_fields_dirty_clob); // array to string to fill 'returning' clause in the sql
        $into_stmt = implode(", ", $into); // array to string to fill 'into' clause in the sql

        $sql = "UPDATE " . static::tableName() . "
                    SET " . $set_stmt . "
                    WHERE " . $where_stmt
        ;
        if ($returning && $into_stmt) {
            $sql .= " RETURNING " . $returning . "
                    INTO " . $into_stmt
            ;
        }
        
        $stmt  = oci_parse($db, $sql);
        $my_lob = [];
        // just see http://www.oracle.com/technology/pub/articles/oracle_php_cookbook/fuecks_lobs.html
        // you'll get it i'm sure
        foreach ($into as $key => $value) {
            $my_lob[$key] = oci_new_descriptor($db, OCI_D_LOB);
            oci_bind_by_name($stmt, $value, $my_lob[$key], -1, OCI_B_CLOB);
            //oci_bind_by_name($stmt, $value, $my_lob[$key], -1, OCI_B_BLOB);
        }
        foreach ($fields_dirty as $name => $value) { // don't use $value in oci_bind_by_name! the link inside this variable is changing
            if (!in_array($name, $fields_clob)) {
                oci_bind_by_name($stmt, ":".$name, $fields_dirty[$name]);
            }
        }
        $result = oci_execute($stmt, OCI_DEFAULT); // or die ("Unable to execute query\n"); //echo oci_error()
        if ($result === false) {
            oci_rollback($db);
            return false;
        }
        if ($exist_fields_dirty_clob) {
            foreach ($exist_fields_dirty_clob as $key => $name) {
                //if (!$my_lob[$key]->savefile( Yii::getAlias('@webroot/uploads/') . $model->files[0]->name )) {
                if (!$my_lob[$key]->save($this->$name)) {
                    oci_rollback($db);
                    return false; //die("Unable to update clob\n");
                }
            }
        }
        oci_commit($db);
        //$my_lob[$key]->free();
        oci_free_statement($stmt);
        oci_close($db); // not sure
        
        $changedAttributes = [];
        $oldArrtibutes = $this->getOldAttributes();
        foreach ($fields_dirty as $name => $value) {
            $changedAttributes[$name] = isset($oldArrtibutes[$name]) ? $oldArrtibutes[$name] : null;
            $this->setOldAttribute($name, $value);
        }
        $this->afterSave(false, $changedAttributes);
        
        return $result;
    }
    
    /**
     * Override ActiveRecord insert() method to fix LOB data insertion
     * 
     * @inheritdoc
     */
    public function insert($runValidation = true, $attributes = null)
    {
        //return parent::insert($runValidation, $attributes);
        
        if ($runValidation && !$this->validate($attributes)) {
            Yii::info('Model not inserted due to validation error.', __METHOD__);
            return false;
        }
        
        if (!$this->beforeSave(true)) {
            return false;
        }
        
        $db = static::getDbOciLob()->getDbh();
        //$fields_blob = static::$blob_attributes;
        $fields_clob = static::$clob_attributes; // array with the fields to be updated
        $fields_dirty = $this->getDirtyAttributes($attributes); // changed fields with values
        $fields_dirty_names = array_keys($fields_dirty);
        $exist_fields_dirty_clob = array_intersect(array_keys($fields_dirty), $fields_clob);
        
        $values = [];
        $into = [];
        foreach ($fields_dirty as $name => $value) {
            if (in_array($name, $fields_clob)) {
                $values[] = "EMPTY_CLOB()";
                $into[] = ":" . $name;
            /*} elseif (in_array($name, $fields_blob)) {
                $values[] = "EMPTY_BLOB()";
                $into[] = ":" . $name;*/
            } else {
                $values[] = ":" . $name;
            }
        }
        $fields_stmt  = implode(", ", $fields_dirty_names);
        $values_stmt  = implode(", ", $values);
        //$returning = implode(", ", $fields_clob + $fields_blob);
        $returning = implode(", ", $fields_clob);
        $into_stmt = implode(", ", $into);

        $sql = "INSERT INTO " . static::tableName() . "
                    (" . $fields_stmt . ")
                    VALUES(" . $values_stmt . ")
        ";
        if ($returning && $into_stmt) {
            $sql .= " RETURNING " . $returning . "
                    INTO " . $into_stmt
            ;
        }

        $stmt  = oci_parse($db, $sql);
        $my_lob = [];
        // just see http://www.oracle.com/technology/pub/articles/oracle_php_cookbook/fuecks_lobs.html
        // you'll get it i'm sure
        foreach ($into as $key => $value) {
            $my_lob[$key] = oci_new_descriptor($db, OCI_D_LOB);
            oci_bind_by_name($stmt, $value, $my_lob[$key], -1, OCI_B_CLOB);
            //oci_bind_by_name($stmt, $value, $my_lob[$key], -1, OCI_B_BLOB);
        }
        foreach ($fields_dirty as $name => $value) { // don't use $value in oci_bind_by_name!
            if (!in_array($name, $fields_clob)) {
                oci_bind_by_name($stmt, ":".$name, $fields_dirty[$name]);
            }
        }
        
        $result = oci_execute($stmt, OCI_DEFAULT); //or die ("Unable to execute query\n"); //echo oci_error()
        if ($result === false) {
            oci_rollback($db);
            return false;
        }
        if ($exist_fields_dirty_clob) {
            foreach ($fields_clob as $key => $name) {
                //if (!$my_lob[$key]->savefile( Yii::getAlias('@webroot/uploads/') . $model->files[0]->name )) {
                if (!$my_lob[$key]->save($this->$name)) {
                    oci_rollback($db);
                    return false; //die("Unable to update clob\n");
                }
            }
        }
        oci_commit($db);
        //$my_lob[$key]->free();
        oci_free_statement($stmt);
        oci_close($db); // not sure

        // Set primary key for new record
        $orderBy = [];
        foreach ($this->primaryKeyOciLob as $attribute) {
            $orderBy[$attribute] = SORT_DESC;
        }
        foreach ($this->primaryKeyOciLob as $attribute) {
            $fields_dirty[$attribute] = $this->find()
                ->orderBy($orderBy)
                ->limit(1)
                ->one()
                ->$attribute;
        }
        
        foreach ($fields_dirty as $name => $value) {
            $id = static::getTableSchema()->columns[$name]->phpTypecast($value);
            $this->setAttribute($name, $id);
            $fields_dirty[$name] = $id;
        }

        $changedAttributes = array_fill_keys(array_keys($fields_dirty), null);
        $this->setOldAttributes($fields_dirty);
        $this->afterSave(true, $changedAttributes);
        
        return $result;
    }