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1 cze 2021 · Standard SQL Functions Cheat Sheet. TEXT FUNCTIONS. CONCATENATION. Use the || operator to concatenate two strings: SELECT 'Hi ' || 'there!'; -- result: Hi there! Remember that you can concatenate only character strings using ||. Use this trick for numbers: SELECT '' || 4 || 2; -- result: 42.
SQL Handwritten Notes Repository: A collection of PDF notes covering SQL concepts with concise definitions and examples. Explore fundamental commands, date/time functions, joins, and more. Contributions welcome!
1 cze 2021 · Standard SQL Functions Cheat Sheet. TEXT FUNCTIONS. CONCATENATION. Use the || operator to concatenate two strings: SELECT 'Hi ' || 'there!'; -- result: Hi there! Remember that you can concatenate only character strings using. ||. Use this trick for numbers: SELECT '' || 4 || 2;
The SQL cheat sheet provides you with the most commonly used SQL statements for your reference. You can download the SQL cheat sheet as follows: Download 3-page SQL cheat sheet in PDF format. Querying data from a table. Query data in columns c1, c2 from a table. SELECT c1, c2 FROM t; Code language: SQL (Structured Query Language) (sql)
SQL GROUP BY. The GROUP BY clause is usually used with an aggregate function (COUNT, SUM, AVG, MIN, MAX). It groups the rows by a given column value (specified after GROUP BY) then calculates the aggregate for each group and returns that to the screen.
Example: Returns users and their subscriptions, along with a new column called activity_levels that makes a judgement based on the number of subscriptions. SELECT first_name, surname, subscriptions CASE WHEN subscriptions > 10 THEN 'Very active' WHEN Quantity BETWEEN 3 AND 10 THEN 'Active' ELSE 'Inactive' END AS activity_levels FROM users; CHECK
SQL is a standard language for storing, manipulating and retrieving data in databases. Our SQL tutorial will teach you how to use SQL in: MySQL, SQL Server, MS Access, Oracle, Sybase, Informix, Postgres, and other database systems. Start learning SQL now » Examples in Each Chapter.
