BZZ - Modulwiki - modul:m290:learningunits:lu04:theorie
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2026-04-07T23:20:07+00:00BZZ - Modulwiki
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https://wiki.bzz.ch/_media/wiki/logo.pngtext/html2024-10-17T10:33:49+00:00Anonymous (anonymous@undisclosed.example.com)LU06a - Syntax of a DQL-Select statement
https://wiki.bzz.ch/modul/m290/learningunits/lu04/theorie/a_syntax?rev=1729161229&do=diff
LU06a - Syntax of a DQL-Select statement
As we know, SQL stands for Structured Query Language. Consequently, It should come as no surprise that SQL is indeed consistently structured. The figure below shows the structure of a exhaustive SQL statement.text/html2024-10-17T10:34:21+00:00Anonymous (anonymous@undisclosed.example.com)LU06b - SQL-DQL: Select from one table
https://wiki.bzz.ch/modul/m290/learningunits/lu04/theorie/b_onetable?rev=1729161261&do=diff
LU06b - SQL-DQL: Select from one table
The simplest SELECT is reading from a table, as we don't have to deal with the connection between other tables. Let's have a quick look on the different parts of an average SELECT statement. Therefore, we will use our Customer Table as practical example for demonstration purposes.text/html2024-10-17T10:34:36+00:00Anonymous (anonymous@undisclosed.example.com)LU06c - SQL-DQL: Select from multiple tables
https://wiki.bzz.ch/modul/m290/learningunits/lu04/theorie/c_multipletables?rev=1729161276&do=diff
LU06c - SQL-DQL: Select from multiple tables
Source: W3Schools.co: SELECT with WHERE
As we know, a RDB essentially consists of tables which are linked together to increase quality and performance and reduce unintended redundancies and inconsistencies. The following ERD shows such a data structure of a shop including some details.text/html2024-10-17T10:34:44+00:00Anonymous (anonymous@undisclosed.example.com)LU06d - SQL-DQL: Selects with Aggregate Functions
https://wiki.bzz.ch/modul/m290/learningunits/lu04/theorie/d_complexselects?rev=1729161284&do=diff
LU06d - SQL-DQL: Selects with Aggregate Functions
SQL (Structured Query Language) provides powerful tools to perform calculations and data analysis on database records. Among these tools, aggregate functions play a crucial role in summarizing data by performing operations on multiple rows and returning a single result. This document focuses on five commonly used SQL aggregate functions: