[SQL][psql]基本指令(1)
這篇是整理一些 psql 的基本指令，
內容來自 Udacity 上 Intro to Relational Databases 的免費課程。
BASIC COMMANDS
Connect to psql
$ psqlQuit psql
$ \qList all databases
$ \list
# or
$ \l
# exit from query result viewer
$ qList all datatables in current database
# connect to the database
$ \connect dbname
# or
$ \c dbname
# list all tables
$ \dt### SQL COMMANDS **Create and Drop DATABASE** ``` CREATE DATABASE dbname; DROP DATABASE dbname; ``` **Create and Drop TABLE** ``` # Example: Create a table with a text column and a serial column CREATE TABLE dtname ( id serial, name text );
drop table dtname
DROP TABLE dtname;
**Insert values**INSERT INTO dtname VALUES(‘This is a test’);
**Show all data in a table**TABLE dtname
or
SELECT * FROM dtname
**Set primary key**single column primary key
CREATE TABLE dtname ( id serial primary key, name text, birthday date );
multiple columns primary key
CREATE TABLE postal_places ( postal_code text, country text, name text, primary key (postal_code, country) );
**Declaring relationships**
CREATE TABLE sales ( sku text references products (sku), sale_date date, count integer );