Tutorial by Examples: table

To create a build target producing an executable, one should use the add_executable command: add_executable(my_exe main.cpp utilities.cpp) This creates a build target, e.g. make my_exe for GNU make, with the appropriate invocations of the configured compiler to pr...

You update all rows in table by simply providing a column_name = value: UPDATE person SET planet = 'Earth';

You can update multiple columns in a table in the same statement, separating col=val pairs with commas: UPDATE person SET country = 'USA', state = 'NY' WHERE city = 'New York';

You can also update data in a table based on data from another table: UPDATE person SET state_code = cities.state_code FROM cities WHERE cities.city = city; Here we are joining the person city column to the cities city column in order to get the city's state code. This is then used to updat...

The following command imports CSV files into a MySQL table with the same columns while respecting CSV quoting and escaping rules. load data infile '/tmp/file.csv' into table my_table fields terminated by ',' optionally enclosed by '"' escaped by '"' lines terminated by '\n' ignore 1...

PostgreSQL and SQLite To create a temporary table local to the session: CREATE TEMP TABLE MyTable(...); SQL Server To create a temporary table local to the session: CREATE TABLE #TempPhysical(...); To create a temporary table visible to everyone: CREATE TABLE ##TempPhysicalVisibleToEveryo...

Sometimes when tables are used mostly (or only) for reads, indexing does not help anymore and every little bit counts, one might use selects without LOCK to improve performance. SQL Server SELECT * FROM TableName WITH (nolock) MySQL SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;...

WITH cte AS ( SELECT ProjectID, ROW_NUMBER() OVER (PARTITION BY ProjectID ORDER BY InsertDate DESC) AS rn FROM ProjectNotes ) DELETE FROM cte WHERE rn > 1;

This script, from here and here, will return all Tables and Columns where a specified value exists. This is powerful in finding out where a certain value is in a database. It can be taxing, so it is suggested that it be executed in a backup / test enviroment first. DECLARE @SearchStr nvarchar(100) ...

Another way you can generate a range of dates is by utilizing a Tally Table to create the dates between the range: Declare @FromDate Date = '2014-04-21', @ToDate Date = '2014-05-02' ;With E1(N) As (Select 1 From (Values (1), (1), (1), (1), (1), (1), (1), (1), (1), (1)) DT...

To delete all rows from the table //get writable database SQLiteDatabase db = openHelper.getWritableDatabase(); db.delete(TABLE_NAME, null, null); db.close(); To delete all rows from the table and get the count of the deleted row in return value //get writable database SQLiteDatabase db =...

One could easily center a child element using table display property. HTML <div class="wrapper"> <div class="parent"> <div class="child"></div> </div> </div> CSS .wrapper { display: table; vertica...

Creating a managed table with partition and stored as a sequence file. The data format in the files is assumed to be field-delimited by Ctrl-A (^A) and row-delimited by newline. The below table is created in hive warehouse directory specified in value for the key hive.metastore.warehouse.dir in the ...

Just define: // These rules give anyone, even people who are not users of your app, // read and write access to your database { "rules": { ".read": true, ".write": true } } It can be useful during development but pay attention because This level o...

Another use of RODBC is in connecting with SQL Server Management Database. We need to specify the 'Driver' i.e. SQL Server here, the database name "Atilla" and then use the sqlQuery to extract either the full table or a fraction of it. library(RODBC) cn <- odbcDriverConnect(connect...

When creating tables it is possible to declare a column as nullable or non-nullable. CREATE TABLE MyTable ( MyCol1 INT NOT NULL, -- non-nullable MyCol2 INT NULL -- nullable ) ; By default every column (except those in primary key constraint) is nullable unless we explicitly set ...

You create new ScriptableObject instances through ScriptableObject.CreateInstance<T>() T obj = ScriptableObject.CreateInstance<T>(); Where T extends ScriptableObject. Do not create ScriptableObjects by calling their constructors, ie. new ScriptableObject(). Creating ScriptableO...

Extra care should be taken when accessing serialized fields in a ScriptableObject instance. If a field is marked public or serialized through SerializeField, changing its value is permanent. They do not reset when exiting playmode like MonoBehaviours do. This can be useful at times, but it can also...

dplyr introduces a grammar of data manipulation in R. It provides a consistent interface to work with data no matter where it is stored: data.frame, data.table, or a database. The key pieces of dplyr are written using Rcpp, which makes it very fast for working with in-memory data. dplyr's philosoph...

DECLARE @startdate CHAR(8), @numberDays TINYINT SET @startdate = '20160101' SET @numberDays = 10; WITH CTE_DatesTable AS ( SELECT CAST(@startdate as date) AS [date] UNION ALL SELECT DATEADD(dd, 1, [date]) FROM CTE_DatesTable WHERE DATEADD(dd, 1, [date]) <= DateAdd(DAY, @nu...