Tutorial by Examples: n

Let's say we have a simple table called person: CREATE TABLE person ( person_id BIGINT, name VARCHAR(255). age INT, city VARCHAR(255) ); The most basic insert involves inserting all values in the table: INSERT INTO person VALUES (1, 'john doe', 25, 'new york'); If you wa...

You can insert multiple rows in the database at the same time: INSERT INTO person (name, age) VALUES ('john doe', 25), ('jane doe', 20);

You can insert data in a table as the result of a select statement: INSERT INTO person SELECT * FROM tmp_person WHERE age < 30; Note that the projection of the select must match the columns required for the insert. In this case, the tmp_person table has the same columns as person.

Beware that numbers can accidentally be converted to strings or NaN (Not a Number). JavaScript is loosely typed. A variable can contain different data types, and a variable can change its data type: var x = "Hello"; // typeof x is a string x = 5; // changes typeof x to...

GridViews allow commands to be sent from a GridView row. This is useful for passing row-specific information into an event handler as command arguments. To subscribe to a command event: <asp:GridView ID="GridView1" ... OnRowCommand="GridView1_RowCommand"> Buttons are t...

You can also apply a mixin globally. Use caution! Once you apply a mixin globally, it will affect every Vue instance created afterwards. When used properly, this can be used to inject processing logic for custom options: // inject a handler for `myOption` custom option Vue.mixin({ created: func...

When custom options are merged, they use the default strategy, which simply overwrites the existing value. If you want a custom option to be merged using custom logic, you need to attach a function to Vue.config.optionMergeStrategies: Vue.config.optionMergeStrategies.myOption = function (toVal, fro...

When a mixin and the component itself contain overlapping options, they will be “merged” using appropriate strategies. For example, hook functions with the same name are merged into an array so that all of them will be called. In addition, mixin hooks will be called before the component’s own hooks:...

Let's say you have a service the same as the one defined in the "First service and host" example. To create a client, define the client configuration section in the system.serviceModel section of your client configuration file. <system.serviceModel> <services> <cli...

Add the following pom to the dependencies section of your gradle build file : project.dependencies { compile 'org.roboguice:roboguice:3.+' provided 'org.roboguice:roboblender:3.+' }

The @ContentView annotation can be used to further alleviate development of activities and replace the setContentView statement : @ContentView(R.layout.myactivity_layout) public class MyActivity extends RoboActivity { @InjectView(R.id.text1) TextView textView; @Override protected ...

You can inject any type of resource, Strings, Animations, Drawables, etc. To inject your first resource into an activity, you'll need to: Inherit from RoboActivity Annotate your resources with @InjectResource Example @InjectResource(R.string.app_name) String name; @InjectResource(R.drawa...

You can inject any view using the @InjectView annotation: You'll need to: Inherit from RoboActivity Set your content view Annotate your views with @InjectView Example @InjectView(R.id.textView1) TextView textView1; @InjectView(R.id.textView2) TextView textView2; @InjectView(R.id.imag...

The UIAlertController available since iOS8 allows you to use the same alert object for either Action sheets or more classic alerts. The only difference is the UIAlertControllerStyle passed as a parameter when creating. This line changes from an AlertView to an ActionSheet, compared to some other ex...

User input Imagine you want a user to enter a number via input. You want to ensure that the input is a number. You can use try/except for this: Python 3.x3.0 while True: try: nb = int(input('Enter a number: ')) break except ValueError: print('This is not a num...

Func provides a holder for parameterised anonymous functions. The leading types are the inputs and the last type is always the return value. // square a number. Func<double, double> square = (x) => { return x * x; }; // get the square root. // note how the signature matches the built ...

Functions have two built-in methods that allow the programmer to supply arguments and the this variable differently: call and apply. This is useful, because functions that operate on one object (the object that they are a property of) can be repurposed to operate on another, compatible object. Addi...

If you have a variable declared before, you can assign some value to it: For example: int a; // declared previously a = 2; Or change the value: int a = 3; // initalized previously a = 2;

DECLARE @VariableName INT SET @VariableName = 1 PRINT @VariableName 1 Using SET, you can only update one variable at a time.

Using SELECT, you can update multiple variables at once. DECLARE @Variable1 INT, @Variable2 VARCHAR(10) SELECT @Variable1 = 1, @Variable2 = 'Hello' PRINT @Variable1 PRINT @Variable2 1 Hello When using SELECT to update a variable from a table column, if there are multiple values, it wi...