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PostgreSQL
Wha is it?
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PostgreSQL is a general purpose and object-relational database management system.
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Most advanced open source database system.
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it could run on various platforms such as Mac OS X, Solaris, and Windows.
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Developed based on POSTGRES 4.2 at Berkeley Computer Science Department, University of California.
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PostgreSQL features:
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Table inheritance
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Native Microsoft Windows Server version
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Tablespaces
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User-defined types
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more
Installation Process
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Google the software name; postgresql.
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Click on the Download page of the official site.
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Select the Operating system.
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Choose the software version and OS bit version from drop-down menu.
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Select the download now button to start download.
Opening PostgreSQL
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Search pgAdmin in windows search bar.
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Open that application for manipulating with the database.
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This is the window looks like.
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Here we need to connect to the server.
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Click on Server on left > Select PostgreSQL 10 > provide passoword > OK.
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To create a database, right click on Databases > Create > Database > give a name of Database > set owner > Save.
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To create a table, click on Tools on menu > Query Tool.
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A query window will appear on right as below.
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Write the query and execute by pressing F5, or execute button.
PostgreSQL Data Type
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The kind of data you want to store in the table fields.
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PostgreSQL supports a wide set of Data Types.
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Besides, users can create their own custom data type using CREATE TYPE SQL command.
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The followings are the datatypes:
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Numeric Types
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Monetary Types
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Character Types
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Binary Data Types
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Data/Time Type
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Boolean Type
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Enumerated Type
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Geometric Type
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Network Address Type
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XML Types
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JSON Type
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Array Type
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Composite Types
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Object Identifier Types​
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Pseudo Types
PostgreSQL Queries
SELECT Data
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want to know the first name, last name and email of customers, you can specify the column names in the SELECT statement as follows:
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SELECT first_name, last_name, email FROM customer;
INSERT Data
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When you create a new table, it does not have any data. The first thing you often do is to insert new rows into the table.
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Syntax: INSERT INTO table(column1, column2, …) VALUES (value1, value2, …);
UPDATE Data
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To change the values of the columns in a table, you use the UPDATE statement.
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Syntax: UPDATE table SET column1 = value1, column2 = value2 ,... WHERE condition;
FILTER Data
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WHERE clause to filter rows returned from the SELECT statement.
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Syntax: ​SELECT column_1, column_2 … column_n FROM table_name WHERE conditions;
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Example: ​SELECT last_name, first_name FROM customer WHERE first_name = 'Jamie' AND last_name = 'Rice';
DELETE Data
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To delete data from a table, you use PostgreSQL DELETE statement as shown below:
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DELETE FROM table WHERE condition;
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