SQL skills are essential for high-demand roles like data analyst, business analyst, data scientist, software developer, and database administrator. Mastering SQL enables professionals to efficiently ...

In this Microsoft SQL Server and JDBC tutorial, you'll learn how to connect to a Microsoft SQL Server in Java using JDBC. The steps are relatively straightforward: Each database is different, so ...

SQL, the Structured Query Language, is a cornerstone skill for anyone working with data. To master this powerful language, consistent practice is crucial. We present a curated list of 12 top-notch ...

SQL is a tool that is widely used in the manipulation of data and featuring in the relational database. They are applied in querying, manipulating as well as reporting data and it is commonly used by ...

The real power comes when we start aggregating our sql data using aggregate functions such as COUNT (), SUM (), AVG () etc., These let us analyze patterns across multiple tables without needing ...

最近在搞新项目，一直在迭代，这期接到个新需求，统计商户近 1天、7天、30天、全部的订单量。 一般而言这种统计类需求都不会直接查库，而是交由数仓同学统计，然后回写到业务表或者业务同学直接读数仓表。 但是由于这是新项目，还没接数仓，并且量还没 ...

Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement. It’s sometimes difficult to know which SQL syntax to use when ...