Tutorial by Examples: field

To print a test field (TestField) from a test feature class (TestFC) in a test file geodatabase (Test.gdb) located in a temporary folder (C:\Temp): with arcpy.da.SearchCursor(r"C:\Temp\Test.gdb\TestFC",["TestField"]) as cursor: for row in cursor: print row[0]

Sometimes it's useful to check if a field is present or absent on your JSON to avoid some JSONException on your code. To achieve that, use the JSONObject#has(String) or the method, like on the following example: Sample JSON { "name":"James" } Java code String jsonStr...

Ordering directly on JSONField is not yet supported in Django. But it's possible via RawSQL using PostgreSQL functions for jsonb: from django.db.models.expressions import RawSQL RatebookDataEntry.objects.all().order_by(RawSQL("data->>%s", ("json_objects_key",))) This e...

To initialize a static final fields that require using more than a single expression, a static initializer can be used to assign the value. The following example initializes a unmodifiable set of Strings: public class MyClass { public static final Set<String> WORDS; static {...

OPENJSON function parses collection of JSON objects and returns values from JSON text as set of rows. If the values in input object are nested, additional mapping parameter can be specified in each column in WITH clause: declare @json nvarchar(4000) = N'[ {"data":{"num":&quot...

To build up an expression like _ => _.Field == "VALUE" at runtime. Given a predicate _ => _.Field and a string value "VALUE", create an expression that tests whether or not the predicate is true. The expression is suitable for: IQueryable<T>, IEnumerable<T>...

If we have a Model as following, from django.db import models from django.contrib.auth.models import User class UserModuleProfile(models.Model): user = models.OneToOneField(User) expired = models.DateTimeField() admin = models.BooleanField(default=False) employee_id = models...

A bit field is a variable that holds various boolean states as individual bits. A bit on would represent true, and off would be false. In the past bit fields were routinely used as they saved memory and reduced processing load. Though the need to use bit field is no longer so important they do offer...

Given the text file employee.txt 1|Arthur Dent 2|Marvin 3|Zaphod Beeblebrox $ mysqlimport --fields-terminated-by='|' mycompany employee.txt

DateTimeField is used to store date time values. class MyModel(models.Model): start_time = models.DateFimeField(null=True, blank=True) created_on = models.DateTimeField(auto_now_add=True) updated_on = models.DateTimeField(auto_now=True) A DateTimeField has two optional parameters:...

Having example type like this: public TestClass { public static string StaticPublicField = "StaticPublicFieldValue"; } We can retrieve value of StaticPublicField: var fieldExpr = Expression.Field(null, typeof(TestClass), "StaticPublicField"); var labmda = Expression....

Let's assume that the field separator is : (colon) in the file file. while IFS= read -d : -r field || [ -n "$field" ]; do echo "$field" done <file For a content: first : se con d: Thi rd: Fourth The output is: **first ** ** se con d** ** Thi ...

Let's assume that the field separator is : var='line: 1 line: 2 line3' while IFS= read -d : -r field || [ -n "$field" ]; do echo "-$field-" done <<< "$var" Output: -line- - 1 line- - 2 line3 -

Let's assume that the field separator is : arr=() while IFS= read -d : -r field || [ -n "$field" ]; do arr+=("$field") done <file

Let's assume that the field separator is : var='1:2:3:4: newline' arr=() while IFS= read -d : -r field || [ -n "$field" ]; do arr+=("$field") done <<< "$var" echo "${arr[4]}" Output: newline

Let's assume that the field separator is : while IFS= read -d : -r field || [ -n "$field" ];do echo "**$field**" done < <(ping google.com) Or with a pipe: ping google.com | while IFS= read -d : -r field || [ -n "$field" ];do echo "**$field**&q...

Every instance of WWW with a second parameter is a post. Here is an example to post user id and password to server. void Login(string id, string pwd) { WWWForm dataParameters = new WWWForm(); // Create a new form. dataParameters.AddField("username", id); dataParameter...

Defining the base class: open class BaseClass { val x = 10 } Defining the derived class: class DerivedClass: BaseClass() { fun foo() { println("x is equal to " + x) } } Using the subclass: fun main(args: Array<String>) { val derivedClass = Deri...

Bit-fields give an ability to declare structure fields that are smaller than the character width. Bit-fields are implemented with byte-level or word-level mask. The following example results in a structure of 8 bytes. struct C { short s; /* 2 bytes */ char c; /* 1 ...

Apart from primitives, the Explicit Layout structs (Unions) in C#, can also contain other Structs. As long as a field is a Value type and not a Reference, it can be contained in a Union: using System; using System.Runtime.InteropServices; // The struct needs to be annotated as "Explici...