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In Oracle a DATE data type does not have a format; when Oracle sends a DATE to the client program (SQL/Plus, SQL/Developer, Toad, Java, Python, etc) it will send 7- or 8- bytes which represent the date. A DATE which is not stored in a table (i.e. generated by SYSDATE and having "type 13" ...

Use TO_CHAR( date [, format_model [, nls_params]] ): (Note: if a format model is not provided then the NLS_DATE_FORMAT session parameter will be used as the default format model; this can be different for every session so should not be relied on. It is good practice to always specify the format mod...

When Oracle implicitly converts from a DATE to a string or vice-versa (or when TO_CHAR() or TO_DATE() are explicitly called without a format model) the NLS_DATE_FORMAT session parameter will be used as the format model in the conversion. If the literal does not match the format model then an excepti...

When SQL/Plus or SQL Developer display dates they will perform an implicit conversion to a string using the default date format model (see the Setting the Default Date Format Model example). You can change how a date is displayed by changing the NLS_DATE_FORMAT parameter.

CREATE CONTEXT my_ctx USING my_pkg; This creates a context that can only be set by routines in the database package my_pkg, e.g.: CREATE PACKAGE my_pkg AS PROCEDURE set_ctx; END my_pkg; CREATE PACKAGE BODY my_pkg AS PROCEDURE set_ctx IS BEGIN DBMS_SESSION.set_context('MY_CTX','...

When it comes to geographic data, R shows to be a powerful tool for data handling, analysis and visualisation. Often, spatial data is avaliable as an XY coordinate data set in tabular form. This example will show how to create a spatial data set from an XY data set. The packages rgdal and sp provi...

The difference between size and count is: size counts NaN values, count does not. df = pd.DataFrame( {"Name":["Alice", "Bob", "Mallory", "Mallory", "Bob" , "Mallory"], "City":["Seattle", &q...

var a:Object; trace(a); // null trace(a.b); // Error 1009 Here, an object reference is declared, but is never assigned a value, be it with new or assignment of a non-null value. Requesting its properties or method results in a 1009 error.

prerequisite of scrapy installation: Python 2.7 or above 3.3 pip and setuptools Python packages. lxml OpenSSL. You can install Scrapy using pip. To install using pip run: pip install Scrapy Platform specific installation Anaconda This is the recommended way to install Scrapy. ...

4.0 Declare an associative array declare -A aa Declaring an associative array before initialization or use is mandatory. Initialize elements You can initialize elements one at a time as follows: aa[hello]=world aa[ab]=cd aa["key with space"]="hello world" You can al...

Windows There are two options how to install Kivy: First ensure python tools are up-to-date. python -m pip install --upgrade pip wheel setuptools Then install the basic dependencies. python -m pip install docutils pygments pypiwin32 kivy.deps.sdl2 kivy.deps.glew Although Kivy already has p...

You can install three.js via npm: npm install three You can add it from a CDN to your HTML: <script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r83/three.js"></script> You can use the three.js editor to give it a try and download the project as an ex...

Arithmetic if statement allows one to use three branches depending on the result of an arithmetic expression if (arith_expr) label1, label2, label3 This if statement transfers control flow to one of the labels in a code. If the result of arith_expr is negative label1 is involved, if the result i...

Detailed instructions on getting tfs set up or installed.

This validation restricts the insertion of only numeric values. class Player < ApplicationRecord validates :points, numericality: true validates :games_played, numericality: { only_integer: true } end Besides :only_integer, this helper also accepts the following options to add constrai...

This helper validates that the attribute's value is unique right before the object gets saved. class Account < ApplicationRecord validates :email, uniqueness: true end There is a :scope option that you can use to specify one or more attributes that are used to limit the uniqueness check: ...

This helper validates that the specified attributes are not empty. class Person < ApplicationRecord validates :name, presence: true end Person.create(name: "John").valid? # => true Person.create(name: nil).valid? # => false You can use the absence helper to validate th...

Use following methods if you want to skip the validations. These methods will save the object to the database even if it is invalid. decrement! decrement_counter increment! increment_counter toggle! touch update_all update_attribute update_column update_columns update_counters You ca...

class Person < ApplicationRecord validates :name, length: { minimum: 2 } validates :bio, length: { maximum: 500 } validates :password, length: { in: 6..20 } validates :registration_number, length: { is: 6 } end The possible length constraint options are: :minimum - The attribut...

Unlike Big-O notation, which represents only upper bound of the running time for some algorithm, Big-Theta is a tight bound; both upper and lower bound. Tight bound is more precise, but also more difficult to compute. The Big-Theta notation is symmetric: f(x) = Ө(g(x)) <=> g(x) = Ө(f(x)) An ...