Tutorial by Examples: le

Below are some tips to remember while we are writing a select query in MySQL that can help us and reduce our query time:- Whenever we use where in a large table we should make sure the column in where clause are index or not. Ex:- Select * from employee where user_id > 2000. user_id if ind...

A module is a collection of related reusable functions (or cmdlets) that can easily be distributed to other PowerShell users and used in multiple scripts or directly in the console. A module is usually saved in it's own directory and consists of: One or more code files with the .psm1 file extensi...

Temporary tables could be very useful to keep temporary data. Temporary tables option is available in MySQL version 3.23 and above. Temporary table will be automatically destroyed when the session ends or connection is closed. The user can also drop temporary table. Same temporary table name can b...

Drop Temporary Table is used to delete the temporary table which you are created in your current session. DROP TEMPORARY TABLE tempTable1 DROP TEMPORARY TABLE IF EXISTS tempTable1 Use IF EXISTS to prevent an error occurring for tables that may not exist

To easily select a buffer by filename, you can use: :b [part_of_filename]<Tab><Tab><Tab>...<Enter> The first Tab will expand the word to a full filename, and subsequent Tab presses will cycle through the list of possible matches. When multiple matches are available, you ...

extension String { func matchesPattern(pattern: String) -> Bool { do { let regex = try NSRegularExpression(pattern: pattern, options: NSRegularExpressionOptions(rawValue: 0)) let range: NSRange = NSMakeRange(...

super keyword performs important role in three places Constructor Level Method Level Variable Level Constructor Level super keyword is used to call parent class constructor. This constructor can be default constructor or parameterized constructor. Default constructor : super(); Pa...

Often one want to show the result of a command executed by root to other users. The tee command allows easily to write a file with user perms from a command running as root: su -c ifconfig | tee ~/results-of-ifconfig.txt Only ifconfig runs as root.

Consider this example: public class ThreadTest implements Runnable { private boolean stop = false; public void run() { long counter = 0; while (!stop) { counter = counter + 1; } System.out.println("Counted " + counter);...

local t1, t2, t3, t4 = {}, {}, {}, {} -- Create 4 tables local maintab = {t1, t2} -- Regular table, strong references to t1 and t2 local weaktab = setmetatable({t1, t2, t3, t4}, {__mode = 'v'}) -- table with weak references. t1, t2, t3, t4 = nil, nil, nil, nil -- No more "strong" refe...

If you want to have a table organized in column-store format instead of row store, add INDEX cci CLUSTERED COLUMNSTORE in definition of table: DROP TABLE IF EXISTS Product GO CREATE TABLE Product ( ProductID int, Name nvarchar(50) NOT NULL, Color nvarchar(15), Size nvarchar(5)...

CREATE CLUSTERED COLUMNSTORE INDEX enables you to organize a table in column format: DROP TABLE IF EXISTS Product GO CREATE TABLE Product ( Name nvarchar(50) NOT NULL, Color nvarchar(15), Size nvarchar(5) NULL, Price money NOT NULL, Quantity int ) GO CREATE CLUSTERED C...

Erlang on OpenBSD is currently broken on alpha, sparc and hppa architectures. Method 1 - Pre-built Binary Package OpenBSD let you choose desired version you want to install on your system: ###################################################################### # free-choice: ####################...

Consider the following partial example: import com.example.somelib.*; import com.acme.otherlib.*; public class Test { private Context x = new Context(); // from com.example.somelib ... } Suppose that when when you first developed the code against version 1.0 of somelib and versi...

In this iText 5 example, we need to switch between different styles in the same document: The best way to do this in iText 5, is to create a convenience method that creates a Chunk in the style that needs to be used frequently; see the createBgChunk() method: public Chunk createBgChunk(String s,...

In this iText 7 example, we need to switch between different styles in the same document: The best way to achieve this in iText 7, is to create a Style object, and to apply that Style to a Text object: public void createPdf(String dest) throws IOException { PdfDocument pdf = new PdfDocument...

In this example, we'll create the following table using iText 5: We need the PdfPTable and PdfPCell class to achieve this: public void createPdf(String dest) throws IOException, DocumentException { Document document = new Document(); PdfWriter.getInstance(document, new FileOutputStream...

In this example, we'll create the following table using iText 7: We'll need the Table and Cell class to achieve this: public void createPdf(String dest) throws IOException { PdfDocument pdf = new PdfDocument(new PdfWriter(dest)); try (Document document = new Document(pdf)) { T...

Executable JAR files are the simplest way to assemble Java code into a single file that can be executed. *(Editorial Note: Creation of JAR files should be covered by a separate Topic.) * Assuming that you have an executable JAR file with pathname <jar-path>, you should be able to run it as f...

An NSPredicate can use substitution variables to allow values to be bound on the fly. Objective-C NSPredicate *template = [NSPredicate predicateWithFormat: @"self BEGINSWITH $letter"]; NSDictionary *variables = @{ @"letter": @"r" }; NSPredicate *beginsWithR = [templ...