Search results
Results from the WOW.Com Content Network
The SQL:1999 standard introduced a BOOLEAN data type as an optional feature (T031). When restricted by a NOT NULL constraint, a SQL BOOLEAN behaves like Booleans in other languages, which can store only TRUE and FALSE values. However, if it is nullable, which is the default like all other SQL data types, it can have the special null value also.
For example: If stock=0 Then message= order new stock Else message= there is stock End If. In the example code above, the part represented by (Boolean condition) constitutes a conditional expression, having intrinsic value (e.g., it may be substituted by either of the values True or False) but having no intrinsic meaning
The boolean expression must be a compile-time constant value, for example (sizeof(int)==4) would be a valid expression in that context. This construct does not work at file scope (i.e. not inside a function), and so it must be wrapped inside a function. Another popular [3] way of implementing assertions in C is:
In all versions of Python, boolean operators treat zero values or empty values such as "", 0, None, 0.0, [], and {} as false, while in general treating non-empty, non-zero values as true. The boolean values True and False were added to the language in Python 2.2.1 as constants (subclassed from 1 and 0) and were changed to be full blown keywords ...
In computer science, a Boolean expression is an expression used in programming languages that produces a Boolean value when evaluated. A Boolean value is either true or false.A Boolean expression may be composed of a combination of the Boolean constants True/False or Yes/No, Boolean-typed variables, Boolean-valued operators, and Boolean-valued functions.
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 ...
[3] The precondition, and the definition of exception, is subjective. The set of "normal" circumstances is defined entirely by the programmer, e.g. the programmer may deem division by zero to be undefined, hence an exception, or devise some behavior such as returning zero or a special "ZERO DIVIDE" value (circumventing the need for exceptions). [4]
This computer-programming -related article is a stub. You can help Wikipedia by expanding it.