Category Archives: sql Certificate

Khóa học miễn phí SQL – Using the Group Functions nhận dự án làm có lương

SQL – Using Group functions Reporting Aggregate data using the Group functions SQL has numerous predefined aggregate functions that can be used to write queries to produce exactly this kind of information.The GROUP BY clause specifies how to group rows from a data table when aggregating information, while the HAVING clause filters out rows that […]

Khóa học miễn phí SQL – Restricting and Sorting Data nhận dự án làm có lương

SQL – Restricting and Sorting Data The essential capabilities of SELECT statement are Selection, Projection and Joining. Displaying specific columns from a table is known as a project operation. We will now focus on displaying specific rows of output. This is known as a select operation. Specific rows can be selected by adding a WHERE […]

Khóa học miễn phí SQL – The SQL SELECT Statement nhận dự án làm có lương

SQL – The SQL SELECT Statement Questions 1. Identify the capabilities of SELECT statement. Projection Selection Data Control Transaction Answer: A, B. The SELECT statement can be used for selection, projection and joining. 2. Determine the capability of the SELECT statement demonstrated in the given query. SELECT e.ename, d.dname FROM emp e, dept d WHERE […]