Tutorial by Examples: database



DatabaseTransactions trait allows databases to rollback all the change during the tests. If you want to rollback multiple databases , you need to set $connectionsToTransact properties use Illuminate\Foundation\Testing\DatabaseMigrations; class ExampleTest extends TestCase { use Databas...
Create a DATABASE. Note that the shortened word SCHEMA can be used as a synonym. CREATE DATABASE Baseball; -- creates a database named Baseball If the database already exists, Error 1007 is returned. To get around this error, try: CREATE DATABASE IF NOT EXISTS Baseball; Similarly, DROP DATA...
Prolog categorizes everything into: Atoms - Any sequence of characters that do not start with an uppercase alphabet. Eg - a, b, okay Numbers - There is no special syntax for numbers, no declaration is required. Eg 1, 22, 35.8 Variables - A string which starts with an uppercase character or unde...
Once you get past your 'Hello World' app, you'll need to start paying attention to your collection and document schemas, and will need some tools for managing your database. Robomongo - A longtime community favorite for managing Mongo. Highly recommended. JSON Generator - Invaluable utility for...
The first thing you need to do is create a connection to the database using the connect method. After that, you will need a cursor that will operate with that connection. Use the execute method of the cursor to interact with the database, and every once in a while, commit the changes using the comm...
General Using the package RMySQL we can easily query MySQL as well as MariaDB databases and store the result in an R dataframe: library(RMySQL) mydb <- dbConnect(MySQL(), user='user', password='password', dbname='dbname',host='127.0.0.1') queryString <- "SELECT * FROM table1 t1 JO...
Specifies how the database generates values for the property. There are three possible values: None specifies that the values are not generated by the database. Identity specifies that the column is an identity column, which is typically used for integer primary keys. Computed specifies that th...
In Visual Studio go to your Solution Explorer then click on Project you will be adding model Right mouse. Choose ADO.NET Entity Data Model Then choose Generate from database and click Next in next window click New Connection... and point to the database you want to generate model from (Could be M...
Below query can be used to get TempDB database details: USE [MASTER] SELECT * FROM sys.databases WHERE database_id = 2 OR USE [MASTER] SELECT * FROM sys.master_files WHERE database_id = 2 With the help of below DMV, you can check how much TempDb space does your session is using. This query...
Opening a database is an asynchronous operation. We need to send a request to open our database and then listen for events so we know when it's ready. We'll open a DemoDB database. If it doesn't exist yet, it will get created when we send the request. The 2 below says that we're asking for version...
The using keyword ensures that the resource defined within the statement only exists within the scope of the statement itself. Any resources defined within the statement must implement the IDisposable interface. These are incredibly important when dealing with any connections that implement the IDi...
A transaction acts on a single database connection. If you have multiple class-specific databases, the transaction will not protect interaction among them. One workaround is to begin a transaction on each class whose models you alter: Student.transaction do Course.transaction do course.enro...
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]
Put your dbname.sqlite or dbname.db file in assets folder of your project. public class Databasehelper extends SQLiteOpenHelper { public static final String TAG = Databasehelper.class.getSimpleName(); public static int flag; // Exact Name of you db file that you put in as...
Resolving scoped services during application startup can be difficult, because there is no request and hence no scoped service. Resolving a scoped service during application startup via app.ApplicationServices.GetService<AppDbContext>() can cause issues, because it will be created in the sc...
Multiple operations can be executed against a single transaction so that changes can be rolled back if any of the operations fail. using (var context = new PlanetContext()) { using (var transaction = context.Database.BeginTransaction()) { try { //Lets assum...
(Caveat emptor: there are many, many programmers who go into absolute conniptions if they meet code that uses recordsets instead of commands and stored procedures.) <% dim rs, sql dim SelectedUser SelectedUser = request.form("user") if IsNumeric(SelectedUser) then SelectedUser...
EXEC sp_MSForEachTable 'ALTER INDEX ALL ON ? REBUILD'
You can default to the normal Mongo format by defining your collections with the idGeneration field. MyCollection = new Meteor.Collection('mycollection', {idGeneration : 'MONGO'});
Information about the database connections SELECT a.mon$attachment_id as Attachment_ID, a.mon$server_pid as Server_PID, case a.mon$state when 1 then 'active' when 0 then 'idle' end as State, a.mon$attachment_name as Database_Name, ...

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