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Predicates, which specify conditions that can be evaluated to SQL three-valued logic (3VL) (true/false/unknown) or Boolean truth values and are used to limit the effects of statements and queries, or to change program flow. Queries, which retrieve the data based on specific criteria. This is an important element of SQL.
SQLyog works on the Windows platform ranging from Windows Vista [10] to Windows 10. (Windows 9x/ME support was removed in version 5.0, Windows 2000 support stopped with version 8.6, and Windows XP support ended with version 12.5.) It has also been made to work under Linux and various Unixes (including macOS) using the Wine environment. [11]
This is also known as a Horizontal Partition, restricting rows output by a query according to specified conditions. With more than one table, the result set will be every combination of rows. So if two tables are T1 and T2, SELECT * FROM T1, T2 will result in every combination of T1 rows with every T2 rows. E.g., if T1 has 3 rows and T2 has 5 ...
It was developed by MySQL AB and later by Sun Microsystems and released under the GPL. Development on the GUI Tools bundle has stopped, and is now [when?] only preserved under the Download Archives of the MySQL site. [9] The GUI Tools bundle has been superseded by MySQL Workbench, and reached its End-of-Life with the beta releases of MySQL ...
In addition to basic equality and inequality conditions, SQL allows for more complex conditional logic through constructs such as CASE, COALESCE, and NULLIF.The CASE expression, for example, enables SQL to perform conditional branching within queries, providing a mechanism to return different values based on evaluated conditions.
MariaDB is intended to maintain high compatibility with MySQL, with exact matching with MySQL APIs and commands, allowing it in many cases to function as a drop-in replacement for MySQL. However, new features are diverging. [7] It includes new storage engines like Aria, ColumnStore, and MyRocks.
To summarize this into a remark distinguishing libre (freedom) software from gratis (zero price) software, the Free Software Foundation says: "Free software is a matter of liberty, not price. To understand the concept, you should think of 'free' as in 'free speech', not as in 'free beer ' ". [22] (See Gratis versus libre.)
The relational calculus consists of two calculi, the tuple relational calculus and the domain relational calculus, that is part of the relational model for databases and provide a declarative way to specify database queries.