用Yii2也有一段时间了,发现Yii2 Framework对Database的操作有非常良好的结构和弹性. 接下来介绍三种数据库操作方式. SQL Command Level: // Get DB componet of Application $db = Yii::$app->db; # Get data form SQL execution $ arrData = $db->createCommand('SELECT * FROM table limit 10') ->queryAl…
/**** Query Builder translated by php攻城师 http://blog.csdn.net/phpgcs Preparing Query Builder 准备 Query Builder Building Data Retrieval Queries 构建数据查找查询 Building Data Manipulation Queries 构建数据操作查询 Building Schema Manipulation Queries构建数据结构操作查询 ****/ Yi…
Active Record: ORM ( Object-relational Mapping)Bridges the gap between relational databases , which are designed around mathematical Set Theory and Object Oriented programming languages that deal with objects and their behavior * Greatly simplifies w…
Debugging a SQL Server query with WinDbg May 13, 2014 · Klaus Aschenbrenner · 5 Comments (Be sure to checkout the FREE SQLpassion Performance Tuning Training Plan - you get a weekly email packed with all the essential knowledge you need to know about…
LINQ's method syntax looks very similar to the query builder methods,except for one big difference:the parameters.Theparameters of a LINQ method ara lambda expressions,whereas the parameters of the query builder methods are Entity SQL string expressi…
refer: http://sqlblog.com/blogs/paul_white/archive/2012/04/28/query-optimizer-deep-dive-part-1.aspx SQL是一种结构化查询语言规范,它从逻辑是哪个描述了用户需要的结果,而SQL服务器将这个逻辑需求描述转成能执行的物理执行计划,从而把结果返回给用户.将逻辑需求转换成一个更有效的物理执行计划的过程,就是优化的过程. 执行SQL的过程: Input Tree We start by looking…
$query = MyModel::find()->where(['not in','attribute',$array]); 參考 Yii2 : Active Record add Not In condition Adding a custom WooCommerce product type How to Set Up WooCommerce Demo Data…
今天写了一个小的SQL语句类似下面的这句: UPDATE A SET ID=B.ID FROM A,B WHERE A.NAME=B.NAME 在执行时居然报了“ORA-00933: SQL command not properly ended”这个错误提示信息,SQL语句如此简单,不应该出现错误的!但是事实上确实报错了,仔细看了下没发现那里有问题,百度了一下,出现这个错误的情况还是挺多的,当抛出此错误提示信息,代表着SQL语句本身就是有问题的!(ORA-00933:SQL命令没有正确的结束)比…
http://guides.rubyonrails.org/active_record_querying.html ✅How to find records using a variety of methods and conditions. ✅How to specify the order, retrieved attributes,grouping, and other properties of the found records. ✅ How to use ).offset(30)将返…