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In addition to SQLSTATE the SQL command GET DIAGNOSTICS offers more details about the last executed SQL command. 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]
SQL statements also include the semicolon (";") statement terminator. Though not required on every platform, it is defined as a standard part of the SQL grammar. Insignificant whitespace is generally ignored in SQL statements and queries, making it easier to format SQL code for readability.
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.
A WHERE clause in SQL specifies that a SQL Data Manipulation Language (DML) statement should only affect rows that meet specified criteria. The criteria are expressed in the form of predicates. WHERE clauses are not mandatory clauses of SQL DML statements, but can be used to limit the number of rows affected by a SQL DML statement or returned ...
Data Control Language is one of the logical group in SQL Commands. SQL [ 1 ] is the standard language for relational database management systems. SQL statements are used to perform tasks such as insert data to a database, delete or update data in a database, or retrieve data from a database.
To reduce contention for table blocks due to insert statements, increase the number of freelists, or buffer frames. To reduce contention for index blocks the best strategy is to implement a reverse index. In most situations the goal is to spread queries over a greater number of blocks, to avoid concentrating on any single one.
In computer programming, a block or code block or block of code is a lexical structure of source code which is grouped together. Blocks consist of one or more declarations and statements . A programming language that permits the creation of blocks, including blocks nested within other blocks, is called a block-structured programming language .
In SQL, a window function or analytic function [1] is a function which uses values from one or multiple rows to return a value for each row. (This contrasts with an aggregate function, which returns a single value for multiple rows.) Window functions have an OVER clause; any function without an OVER clause is not a window function, but rather ...