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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.
Not equal to (many dialects also accept !=) Dept <> 'Sales' > Greater than Hire_Date > '2012-01-31' < Less than Bonus < 50000. 00 >= Greater than or equal Dependents >= 2 <= Less than or equal Rate <= 0. 05 [NOT] BETWEEN [SYMMETRIC] Between an inclusive range. SYMMETRIC inverts the range bounds if the first is higher than the second. Cost ...
The cost is predictable, as every time database system needs to scan full table row by row. When table is less than 2 percent of database block buffer, the full scan table is quicker. Cons: Full table scan occurs when there is no index or index is not being used by SQL. And the result of full scan table is usually slower that index table scan.
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Edgar F. Codd [12] in the early 1970s. [13] This version, initially called SEQUEL (Structured English Query Language), was designed to manipulate and retrieve data stored in IBM's original quasirelational database management system, System R, which a group at IBM San ...
In very early versions of the SQL standard the return code was called SQLCODE and used a different coding schema. The following table lists the standard-conforming values - based on SQL:2011 . [ 1 ] The table's last column shows the part of the standard that defines the row.
Reports defined by RDL can be downloaded to a variety of formats [2] including Excel, PDF, CSV, XML, TIFF (and other image formats [3]), and HTML Web Archive. SQL Server 2008 and 2012 SSRS can also prepare reports in Microsoft Word (DOC) format, while third-party report generators offer additional output formats.
Microsoft accounted for 7.08 percent of the S&P 500. However, in an equal-weight S&P 500 index fund, Microsoft would account for just 0.2 percent of the fund, the same weighting as the other ...
Especially §2.3. Date, C.J. (2000). The Database Relational Model: A Retrospective Review and Analysis: A Historical Account and Assessment of E. F. Codd's Contribution to the Field of Database Technology. Addison Wesley Longman. ISBN 978-0-201-61294-3. Klein, Hans-Joachim (1994). "How to modify SQL queries in order to guarantee sure answers".