PostgreSQL
PostgreSQL is a powerful, open-source object-relational database system that supports SQL and JSON querying. It's known for its robustness, scalability, and high performance. PostgreSQL features include full-text search, concurrency without read locks, and extensibility with custom functions. This makes it ideal for everything from small projects to large enterprise systems.
When an API response returns a list of objects, no matter the amount, pagination is supported. In paginated responses, objects are nested in a data
attribute and have a has_more
attribute that indicates whether you have reached the end of the last page. You can use the starting_after
and endding_before
query parameters to browse pages.
Create Table & Insert Values
When creating a table in postgresSQL it is important to use teh correct
creating a table in PostgreSQL, it is essential to use the correct syntax and configurations to ensure efficient data management and system performance.
- Name
CREATE_TABLE
- Type
- string
- Description
Specifies the SQL command used to create a new table in a database. This command includes the table name and the definition of its columns and their data types, e.g.,
CREATE TABLE table_name (column1 datatype1, column2 datatype2, ...);
.
- Name
CHAR
- Type
- string
- Description
Specifies the use of the CHAR data type for columns where the length of the string is fixed, such as a country code (e.g., 'US', 'CA'). CHAR is more space-efficient when you know the exact length of the data to be stored.
- Name
VARCHAR
- Type
- string
- Description
Specifies the use of the VARCHAR data type for columns that will store strings of variable length. It is ideal for data like names, emails, and addresses where the length can vary.
- Name
PRIMARY_KEY
- Type
- string
- Description
Defines a column or a set of columns that uniquely identifies each row in a table. It is crucial for ensuring data integrity and is often used as an index to enhance the performance of queries that access the table.
Select, Export, View
- Name
\dt
- Type
- string
- Description
Displays the list of relations (tables, sequences, views, etc.) in the database. The command
\dt
is typically used in the psql interactive terminal to view all available tables and relations in the current database.
- Name
SELECT_Command
- Type
- string
- Description
The SELECT command is essential for querying and retrieving data from a database. It is used in almost all SQL operations to select data from tables, and it allows the user to specify columns, conditions, and other clauses.
- Name
Exporting_Results
- Type
- string
- Description
Exporting query results into a file is particularly useful when you need to process or analyze your data outside the database, such as for reporting or further trend analysis. PostgreSQL allows you to export data in various formats like CSV or plain SQL, facilitating data manipulation and sharing.
Creating Table
CREATE TABLE users (
user_id SERIAL PRIMARY KEY,
first_name VARCHAR(50),
last_name VARCHAR(50),
country_code CHAR(2)
);
Insert Values
INSERT INTO users
(first_name,
last_name,
country_code)
VALUES
('Alice', 'Smith', 'GB'),
('Bob', 'Johnson', 'CA'),
('Charlie', 'Brown', 'AU'),
('David', 'Davis', 'US'),
('Emma', 'Garcia', 'MX'),
('Fiona', 'Martinez', 'ES'),
('George', 'Miller', 'US'),
('Hannah', 'Wilson', 'NZ'),
('Ivan', 'Taylor', 'RU'),
('Julia', 'Anderson', 'SE');
Select All
SELECT * FROM users;
Export Selected
COPY (SELECT * FROM users)
TO '/path/to/your/file.csv'
WITH CSV HEADER;