Tutorial by Examples: sql

Since there is no STRING_SPLIT function we need to use XML hack to split the string into rows: Example: SELECT split.a.value('.', 'VARCHAR(100)') AS Value FROM (SELECT Cast ('<M>' + Replace('A|B|C', '|', '</M><M>')+ '</M>' AS XML) AS Data) AS A CROSS apply data...

You can find description of the driver here. The quick example is: import psycopg2 db_host = 'postgres.server.com' db_port = '5432' db_un = 'user' db_pw = 'password' db_name = 'testdb' conn = psycopg2.connect("dbname={} host={} user={} password={}".format( ...

Django supports MySQL 5.5 and higher. Make sure to have some packages installed: $ sudo apt-get install mysql-server libmysqlclient-dev $ sudo apt-get install python-dev python-pip # for python 2 $ sudo apt-get install python3-dev python3-pip # for python 3 As well as ...

Make sure to have some packages installed: sudo apt-get install libpq-dev pip install psycopg2 Database settings for PostgreSQL: #myapp/settings/settings.py DATABASES = { 'default': { 'ENGINE': 'django.db.backends.postgresql', 'NAME': 'myprojectDB', 'USER': '...

sqlite is the default for Django. It should not be used in production since it is usually slow. #myapp/settings/settings.py DATABASES = { 'default': { 'ENGINE': 'django.db.backends.sqlite3', 'NAME': 'db/development.sqlite3', 'USER': '', 'PASSWORD': '', ...

First of all we need to add SQLite support to our application. There are two ways of doing that Download DLL suiting your system from SQLite download page and then add to the project manually Add SQLite dependency via NuGet We'll do it the second way First open the NuGet menu and search f...

/* PL/SQL is a core Oracle Database technology, allowing you to build clean, secure, optimized APIs to SQL and business logic. */ set serveroutput on BEGIN DBMS_OUTPUT.PUT_LINE ('Hello World!'); END;

psycopg2 is the most popular PostgreSQL database adapter that is both lightweight and efficient. It is the current implementation of the PostgreSQL adapter. Its main features are the complete implementation of the Python DB API 2.0 specification and the thread safety (several threads can share t...

So your query has failed (see MySQLi connect for how we made $conn) $result = $conn->query('SELECT * FROM non_existent_table'); // This query will fail How do we find out what happened? $result is false so that's no help. Thankfully the connect $conn can tell us what MySQL told us about the f...

Table locks can be an important tool for ENGINE=MyISAM, but are rarely useful for ENGINE=InnoDB. If you are tempted to use table locks with InnoDB, you should rethink how you are working with transactions. MySQL enables client sessions to acquire table locks explicitly for the purpose of cooperati...

If you need to copy a database from one server to another, you have two options: Option 1: Store the dump file in the source server Copy the dump file to your destination server Load the dump file into your destination server On the source server: mysqldump [options] > dump.sql On th...

While it's good practice to use a Unix based operating system (ex. Linux or BSD) as a production server you can easily install PostgreSQL on Windows (hopefully only as a development server). Download the Windows installation binaries from EnterpriseDB: http://www.enterprisedb.com/products-services-...

To use SQL syntax with model, that would transfer result to proper instantions, you should use directly one of Phalcon\Mvc\Model\Resultset classes: $users = new \Application\Models\Users(); // bitwise operation on `flag` field $sql = 'SELECT * FROM phorum.users WHERE (15 & (1 <&...

A simple PL/pgSQL function: CREATE FUNCTION active_subscribers() RETURNS bigint AS $$ DECLARE -- variable for the following BEGIN ... END block subscribers integer; BEGIN -- SELECT must always be used with INTO SELECT COUNT(user_id) INTO subscribers FROM users WHERE subscribed...

To discover SQL Server's edition, product level and version number as well as the host machine name and the server type: SELECT SERVERPROPERTY('MachineName') AS Host, SERVERPROPERTY('InstanceName') AS Instance, DB_NAME() AS DatabaseContext, SERVERPROPERTY('Editio...

To do this first locate config folder in your root. Then open connections.js Locate // someMysqlServer: { // adapter: 'sails-mysql', // host: 'YOUR_MYSQL_SERVER_HOSTNAME_OR_IP_ADDRESS', // user: 'YOUR_MYSQL_USER', //optional // password: 'YOUR_MYSQL_PASSWORD', //optional /...

Creating a temporal table with a default history table is a convenient option when you want to control naming and still rely on system to create history table with default configuration. In the example below, a new system-versioned memory-optimized temporal table linked to a new disk-based history t...

echo off cls sqlcmd.exe -S "your server name" -U "sql user name" -P "sql password" -d "name of databse" -Q "here you may write your query/stored procedure" Batch files like these can be used to automate tasks, for example to make backups of ...

Configuring the Primary Server Requirements: Replication User for replication activities Directory to store the WAL archives Create Replication user createuser -U postgres replication -P -c 5 --replication + option -P will prompt you for new password + option -c is for max...

There is no single command to rename a MySQL database but a simple workaround can be used to achieve this by backing up and restoring: mysqladmin -uroot -p<password> create <new name> mysqldump -uroot -p<password> --routines <old name> | mysql -uroot -pmypassword <new na...