What are the default rules used by the parser for parsing names of built-in functions?

Actually, when a parser encounters a word that is the name of a built-in function, it must determine whether the name represents a function call or is instead a non-expression reference to an identifier such as a table or column name. consider the following queries −

1. Select sum(salary) from employee;
2. Create table sum (i int);

In the first query SUM is a reference to a function call and in the second query, it is referencing to table name.

Parser follows the following rules to distinguish whether their names are being used as function calls or as identifiers in non-reference context −

• Rule1 − To use the name as a function call in an expression, there must be no whitespace between the name and the following ( parenthesis character).
• Rule2 − Conversely, to use the function name as an identifier, it must not be followed immediately by a parenthesis.

Monica Mona

Published on 21-Feb-2018 08:11:35

• Related Questions & Answers
• How can we change the default rules used by the parser for parsing names of built-in functions?
• What are the default values used by DB2 for various data types?
• What are the scope rules to functions in C programming?
• What are the identity rules for regular expression?
• What are the rules for the body of lambda expression in Java?
• What are the rules for naming classes in C#?
• What are the rules for calling the superclass constructor C++?
• What are the rules for the Subscriber interface in Java 9?
• What are the rules for the Subscription interface in Java 9?
• What are the rules for the Publisher interface in Java 9?
• What are the basic scoping rules for python variables?
• What are the golden rules for handling your money?
• What are the basic rules for defining variables in C++?
• What are the scoping rules for lambda expressions in Java?
• What are the rules for a functional interface in Java?