وصف عن الكتاب:

إذا كنت تستخدم SQL في عملك اليومي كمحلل بيانات أو عالم بيانات أو مهندس بيانات ، فإن دليل الجيب الشهير هذا هو مرجعك المثالي أثناء العمل. ستجد العديد من الأمثلة التي تتناول تعقيدات اللغة ، إلى جانب الجوانب الرئيسية لـ SQL المستخدمة في Microsoft SQL Server و MySQL و Oracle Database و PostgreSQL و SQLite.

في هذا الإصدار المحدث ، يصف المؤلف Alice Zhao كيفية تنفيذ أنظمة إدارة قواعد البيانات هذه لبناء جملة SQL للاستعلام عن قاعدة البيانات وإجراء التغييرات عليها. ستجد تفاصيل حول أنواع البيانات والتحويلات ، وبناء جملة التعبير العادي ، ووظائف النوافذ ، والتمحور وعدم التمحور ، والمزيد.

ابحث بسرعة عن كيفية أداء مهام محددة باستخدام SQL
قم بتطبيق أمثلة بناء جملة الكتاب على استفساراتك الخاصة
قم بتحديث استعلامات SQL للعمل في خمسة أنظمة مختلفة لإدارة قواعد البيانات
جديد: قم بتوصيل Python و R بقاعدة بيانات علائقية
جديد: ابحث عن أسئلة SQL المتداولة في "كيف يمكنني؟" 

If you use SQL in your day-to-day work as a data analyst, data scientist, or data engineer, this popular pocket guide is your ideal on-the-job reference. You'll find many examples that address the language's complexities, along with key aspects of SQL used in Microsoft SQL Server, MySQL, Oracle Database, PostgreSQL, and SQLite.

In this updated edition, author Alice Zhao describes how these database management systems implement SQL syntax for both querying and making changes to a database. You'll find details on data types and conversions, regular expression syntax, window functions, pivoting and unpivoting, and more.

• Quickly look up how to perform specific tasks using SQL
• Apply the book's syntax examples to your own queries
• Update SQL queries to work in five different database management systems
• NEW: Connect Python and R to a relational database
• NEW: Look up frequently asked SQL questions in the "How Do I?" chapter

Why SQL?

Since the last edition of SQL Pocket Guide was published, a lot has changed in the data world. The amount of data generated and collected has exploded, and a number of tools and jobs have been created to handle the influx of data. Through all of the changes, SQL has remained an integral part of the data landscape.

Over the past 15 years, I have worked as an engineer, consultant, analyst, and data scientist, and I have used SQL in every one of my roles. Even if my main responsibilities were focused on another tool or skill, I had to know SQL in order to access data at a company.

If there was a programming language award for best supporting actor, SQL would take home the prize.

As new technologies emerge, SQL is still top of mind when it comes to working with data. Cloud-based storage solutions like Amazon Redshift and Google BigQuery require users to write SQL queries to pull data. Distributed data processing frameworks like Hadoop and Spark have sidekicks Hive and Spark SQL, respectively, which provide SQL-like interfaces for users to analyze data.

SQL has been around for almost five decades, and it is not going away anytime soon. It is one of the oldest programming languages still being used widely today, and I am excited to share the latest and greatest with you in this book.