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In this example a new strong type string named "someString" is created (using Type inference) and the iif function will fill it depending on the outcome of the boolean expression. SQL Server 2012 and newer implements the IIF() function (Transact-SQL):
For example, in a table containing products, one could add a check constraint such that the price of a product and quantity of a product is a non-negative value: price >= 0 quantity >= 0 If these constraints were not in place, it would be possible to have a negative price (−$30) or quantity (−3 items).
Data Analysis Expressions (DAX) is the native formula and query language for Microsoft PowerPivot, Power BI Desktop and SQL Server Analysis Services (SSAS) Tabular models. DAX includes some of the functions that are used in Excel formulas with additional functions that are designed to work with relational data and perform dynamic aggregation .
In the above example, IIf is a ternary function, but not a ternary operator. As a function, the values of all three portions are evaluated before the function call occurs. This imposed limitations, and in Visual Basic .Net 9.0, released with Visual Studio 2008, an actual conditional operator was introduced, using the If keyword instead of IIf ...
For example, a transfer of funds from one bank account to another, even involving multiple changes such as debiting one account and crediting another, is a single transaction. In 1983, [ 1 ] Andreas Reuter and Theo Härder coined the acronym ACID , building on earlier work by Jim Gray [ 2 ] who named atomicity, consistency, and durability, but ...
Major DBMSs, including SQLite, [5] MySQL, [6] Oracle, [7] IBM Db2, [8] Microsoft SQL Server [9] and PostgreSQL [10] support prepared statements. Prepared statements are normally executed through a non-SQL binary protocol for efficiency and protection from SQL injection, but with some DBMSs such as MySQL prepared statements are also available using a SQL syntax for debugging purposes.
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The answers to these example questions may not be the same – the database may have been altered since 1992, causing the queries to produce different results. The valid time and transaction time do not have to be the same for a single fact. For example, consider a temporal database storing data about the 18th century.