Tutorial by Examples: table

When the temp table is created by itself, it will remain while the connection is open. // Widget has WidgetId, Name, and Quantity properties public async Task PurchaseWidgets(IEnumerable<Widget> widgets) { using(var conn = new SqlConnection("{connection string}")) { ...

Immutable is a great library that provides us with immutable versions of widely used types of collections, such as Lists, Stacks, Maps, and more. It simplifies the manipulation of the state and makes it easier to make pure calculations and avoid mutation. Let's see how the Basic reducer can be rew...

The simplest composite type is an immutable type. Instances of immutable types, like tuples, are values. Their fields cannot be changed after they are created. In many ways, an immutable type is like a Tuple with names for the type itself and for each field. Singleton types Composite types, by def...

This UNION ALL combines data from multiple tables and serve as a table name alias to use for your queries: SELECT YEAR(date_time_column), MONTH(date_time_column), MIN(DATE(date_time_column)), MAX(DATE(date_time_column)), COUNT(DISTINCT (ip)), COUNT(ip), (COUNT(ip) / COUNT(DISTINCT (ip))) AS Ratio ...

This simple function will execute the specified Select SQL command and return the result as data set. Public Function ReadFromDatabase(ByVal DBConnectionString As String, ByVal SQL As String) As DataTable Dim dtReturn As New DataTable Try 'Open the connection using the connection...

You can easily create tables for Your database or drop them if You want. If You wish to do that, You should learn how to write Migrations for desired database. Migrations files must be located in config/Migrations folder. File names can be in next formats: YYYYMMDDHHIISS_(Create|Alter|Delete)Ad...

You can set a character set both per table, as well as per individual field using the CHARACTER SET and CHARSET statements: CREATE TABLE Address ( `AddressID` INTEGER NOT NULL PRIMARY KEY, `Street` VARCHAR(80) CHARACTER SET ASCII, `City` VARCHAR(80), `Country` ...

Below is an example for implementing a Search input box that helps users to search the occurances of a particular value across the datatable. In the below example, #report is the div id of the div that contains the search input box. This function is called as soon as the user enters a value in this...

In multiple table UPDATE, it updates rows in each specified tables that satisfy the conditions. Each matching row is updated once, even if it matches the conditions multiple times. In multiple table UPDATE, ORDER BY and LIMIT cannot be used. Syntax for multi table UPDATE is, UPDATE [LOW_PRIORITY]...

SQL Server 2008 The ROW_NUMBER function can assign an incrementing number to each row in a result set. Combined with a Common Table Expression that uses a BETWEEN operator, it is possible to create 'pages' of result sets. For example: page one containing results 1-10, page two containing results 11...

Convert from wide form to long form Load data USArrests from datasets. data("USArrests") head(USArrests) Murder Assault UrbanPop Rape Alabama 13.2 236 58 21.2 Alaska 10.0 263 48 44.5 Arizona 8.1 294 80 31.0 Arkansas 8...

Convert from long form to wide form To recover data from the previous example, use dcast like so. DTc <- dcast(DTmu, State + UrbanPop ~ Crime) This gives the data in the original wide form. State UrbanPop Murder Assault Rape 1: Alabama 58 13.2 236 21.2 2:...

You can create unlogged tables so that you can make the tables considerably faster. Unlogged table skips writing write-ahead log which means it's not crash-safe and unable to replicate. CREATE UNLOGGED TABLE person ( person_id BIGINT NOT NULL PRIMARY KEY, last_name VARCHAR(255) NOT NULL, ...

SQOOP provides facility to import all tables sqoop import-all-tables \ --connect <rdbms-jdbc-url> \ --username <username> \ --password <password> \ --hive-import \ --create-hive-table \ --hive-database <dbname> \ --warehouse-dir <warehouse-dir> Important poin...

The point about temporary tables is that they're limited to the scope of the connection. Dapper will automatically open and close a connection if it's not already opened. That means that any temp table will be lost directly after creating it, if the connection passed to Dapper has not been opened. ...

View tables ActiveRecord::Base.connection.tables Delete any table. ActiveRecord::Base.connection.drop_table("users") ------------OR---------------------- ActiveRecord::Migration.drop_table(:users) ------------OR--------------------- ActiveRecord::Base.connect...

// Let's take a mutable piece of data, a 4-byte integer in this case let mut some_data: u32 = 14; // Create a mutable raw pointer pointing to the data above let data_ptr: *mut u32 = &mut some_data as *mut u32; // Note: creating a raw pointer is totally safe but dereferencing a raw pointe...

select owner, table_name from all_tables ALL_TAB_COLUMNS describes the columns of the tables, views, and clusters accessible to the current user. COLS is a synonym for USER_TAB_COLUMNS. select * from all_tab_columns where table_name = :tname

Getting a table with vertical headers. Twitter bootstrap now support vertical header on a well formatted normal table. To achieve this just use .table-reflow class Use twitter bootstrap .table-reflow class on a well formed table to achieve a table with vertical headers. Additionally you can combin...

DELETE FROM <SCHEMA_NAME>.<Table_NAME> WHERE ctid NOT IN ( SELECT MAX(ctid) FROM <SCHEMA_NAME>.<TABLE_NAME> GROUP BY <SCHEMA_NAME>.<TABLE_NAME>.* ) ;