PostgreSQL Tutorial

• PostgreSQL - Introduction
• Install PostgreSQL on Windows
• Install PostgreSQL on Mac
• PostgreSQL - Loading a Database
• PostgreSQL - Create Database
• PostgreSQL - ALTER DATABASE
• PostgreSQL - DROP DATABASE
• PostgreSQL - Rename Database
• PostgreSQL - Copy Database
• PostgreSQL - Size of a Database
• PostgreSQL - Show Databases

Data Types

• PostgreSQL - Data Types
• PostgreSQL - Boolean Data Type
• PostgreSQL - CHAR Data Type
• PostgreSQL - VARCHAR Data Type
• PostgreSQL - TEXT Data Type
• PostgreSQL - NUMERIC Data Type
• PostgreSQL - SMALLINT Integer Data Type
• PostgreSQL - INTEGER Data Type
• PostgreSQL - BIGINT Integer Data Type
• PostgreSQL - Date Data Type
• PostgreSQL - Timestamp Data Type
• PostgreSQL - UUID Data Type
• PostgreSQL - TIME Data Type
• PostgreSQL - Interval Data Type
• PostgreSQL - User-defined Data Type
• PostgreSQL - Array Data Type
• PostgreSQL - hstore Data Type
• PostgreSQL - JSON Data Type

Querying & Filtering Data

• PostgreSQL - SELECT
• PostgreSQL - SELECT DISTINCT clause
• PostgreSQL - ORDER BY clause
• PostgreSQL - WHERE clause
• PostgreSQL - LIMIT clause
• PostgreSQL - FETCH clause
• PostgreSQL - IN operator
• PostgreSQL - IS NULL operator
• PostgreSQL - LIKE operator
• PostgreSQL - NOT LIKE operator
• PostgreSQL - BETWEEN operator
• PostgreSQL - HAVING clause
• PostgreSQL - GROUP BY clause

Managing Tables

• PostgreSQL - CREATE TABLE
• PostgreSQL - SELECT INTO
• PostgreSQL - Create Auto-increment Column using SERIAL
• PostgreSQL - CREATE SEQUENCE
• PostgreSQL - Identity Column
• PostgreSQL - ALTER TABLE
• PostgreSQL - Rename Table
• PostgreSQL - ADD COLUMN
• PostgreSQL - DROP COLUMN
• PostgreSQL - Change Column Type
• PostgreSQL - RENAME COLUMN
• PostgreSQL - DROP TABLE
• PostgreSQL - TRUNCATE TABLE
• PostgreSQL - Temporary Table
• PostgreSQL - Temporary table name
• PostgreSQL - Removing Temporary Table
• PostgreSQL - Copy a Table
• PostgreSQL - Comparing Tables
• PostgreSQL - Describe Table
• PostgreSQL - Show Tables
• PostgreSQL - Import CSV File Into Table

Modifying Data

• PostgreSQL - INSERT
• PostgreSQL - Insert multiple rows
• PostgreSQL - UPDATE
• PostgreSQL - DELETE
• PostgreSQL - Upsert

Conditionals

• PostgreSQL - CASE
• PostgreSQL - COALESCE
• PostgreSQL - NULLIF() Function
• PostgreSQL - CAST

Control Flow

• PostgreSQL - IF Statement
• PostgreSQL - CASE Statement
• PostgreSQL - Loop Statement
• PostgreSQL - While Loops
• PostgreSQL - For Loops
• PostgreSQL - Exit
• PostgreSQL - Continue

Transactions & Constraints

• PostgreSQL - Transactions
• PostgreSQL - COMMIT
• PostgreSQL - BEGIN
• PostgreSQL - ROLLBACK
• PostgreSQL - Primary Key
• PostgreSQL - Foreign Key
• PostgreSQL - CHECK Constraint
• PostgreSQL - UNIQUE Constraint
• PostgreSQL - NOT NULL Constraint

Working with JOINS & Schemas

• PostgreSQL - Joins
• PostgreSQL - LEFT JOIN
• PostgreSQL - INNER JOIN
• PostgreSQL - FULL OUTER JOIN
• PostgreSQL - SELF JOIN
• PostgreSQL - Schema
• PostgreSQL - CREATE SCHEMA
• PostgreSQL - DROP SCHEMA
• PostgreSQL - ALTER SCHEMA

Roles & Permissions

• PostgreSQL - CREATE ROLE
• PostgreSQL - ALTER ROLE
• PostgreSQL - DROP ROLE
• PostgreSQL - GRANT
• PostgreSQL - REVOKE
• PostgreSQL - Role Membership

Working with Sets

• PostgreSQL - UNION operator
• PostgreSQL - INTERSECT Operator
• PostgreSQL - EXCEPT Operator
• PostgreSQL - GROUPING SETS
• PostgreSQL - CUBE
• PostgreSQL - ROLLUP

Subquery & CTEs

• PostgreSQL - ANY Operator
• PostgreSQL - ALL Operator
• PostgreSQL - EXISTS Operator
• PostgreSQL - CTE
• PostgreSQL - Deleting Duplicate Rows using Subquery

User-defined Functions

• PostgreSQL - CREATE FUNCTION Statement
• PostgreSQL - Function parameter modes
• PostgreSQL - Function Overloading
• PostgreSQL - Function that returns table
• PostgreSQL - Drop Function

Important In-Built Functions

• PostgreSQL - AVG() Function
• PostgreSQL - COUNT() Function
• PostgreSQL - MAX() Function
• PostgreSQL - MIN() Function
• PostgreSQL - SUM() Function
• PostgreSQL - FIRST_VALUE Function
• PostgreSQL - LAST_VALUE Function
• PostgreSQL - NTH_VALUE Function
• PostgreSQL - ROW_NUMBER Function
• PostgreSQL - CURRENT_DATE Function
• PostgreSQL - CURRENT_TIME Function
• PostgreSQL - EXTRACT Function
• PostgreSQL- CONCAT Function
• PostgreSQL - FORMAT Function
• PostgreSQL - UPPER function
• PostgreSQL- LOWER function
• PostgreSQL - REGEXP_MATCHES Function
• PostgreSQL - REGEXP_REPLACE Function
• PostgreSQL - REPLACE Function

PostgreSQL PL/pgSQL

• PostgreSQL - Dollar-Quoted String Constants
• PostgreSQL - Block Structure

Variables & Constants

• PostgreSQL - Variables
• PostgreSQL - Select Into
• PostgreSQL - Row type variables
• PostgreSQL - Record type variable
• PostgreSQL - Constants

Stored Procedures

• PostgreSQL - Introduction to Stored Procedures
• PostgreSQL - CREATE PROCEDURE
• PostgreSQL - Drop Procedure

Working with Triggers

• PostgreSQL - Trigger
• PostgreSQL - CREATE TRIGGER
• PostgreSQL - DROP TRIGGER
• PostgreSQL - ALTER TRIGGER
• PostgreSQL - Disabling a Trigger
• PostgreSQL - Enabling a Trigger

Working with Views & Indexes

• PostgreSQL - CREATE INDEX
• PostgreSQL - DROP INDEX
• PostgreSQL - List Indexes
• PostgreSQL - UNIQUE Index
• PostgreSQL - Partial Index
• PostgreSQL - Index On Expression
• PostgreSQL - REINDEX
• PostgreSQL - Multicolumn Indexes

Errors & Exception Handling

• PostgreSQL - Errors and Messages
• PostgreSQL - Exception Handling
• PostgreSQL - Assert

PostgreSQL - Rename Database

In PostgreSQL, renaming a database is a straightforward task but requires some care. The ALTER DATABASE command is used to rename a database.

Syntax:

ALTER DATABASE old_database_name RENAME TO new_database_name;

Where:

• old_database_name: The current name of the database.
• new_database_name: The new name you want to assign to the database.

Example:

If you wish to rename a database from old_db to new_db, you would use:

ALTER DATABASE old_db RENAME TO new_db;

Important Points to Consider:

1. Connectivity: You cannot rename a database while you or anyone else are connected to it. So, you'd typically need to disconnect from the database you're trying to rename and connect to another database, like the default postgres database.

2. Permissions: Only the database owner or a superuser can rename a database.

3. Application Dependencies: If there are applications or scripts that connect to the database using its name, you'll need to update them to use the new name.

4. Backup: It's always a good idea to take a backup before making structural changes to the database, even if it's just renaming.

Step-by-step to Rename a Database:

1. Connect to a different database, such as the default postgres database:

   psql -U your_username -d postgres
   

2. Rename the database:

   ALTER DATABASE old_db RENAME TO new_db;
   

3. Exit the psql session:

   \q
   

4. Update any configurations, applications, or scripts that reference the old database name.

By following these steps and considering the points mentioned, renaming a database in PostgreSQL can be done smoothly and safely.

1. How to rename a database in PostgreSQL:

   ALTER DATABASE old_database_name RENAME TO new_database_name;
   

2. Changing database name with ALTER DATABASE in PostgreSQL:

   ALTER DATABASE old_database_name RENAME TO new_database_name;
   

3. Renaming the current database in PostgreSQL: Note: You cannot rename the currently connected database. Connect to a different database before renaming.

4. Handling connections and transactions when renaming a database in PostgreSQL: Disconnect or terminate all active connections to the database before renaming. Ensure no active transactions are in progress.

5. Permissions required for renaming a database in PostgreSQL: The user executing the ALTER DATABASE command must have the CREATEDB privilege or be a superuser.

6. Renaming a database with active connections in PostgreSQL: Disconnect or terminate all active connections to the database before renaming. Alternatively, use a maintenance window to minimize disruptions.

7. Using template0 for renaming a database in PostgreSQL: Connect to template0 to perform the rename operation. This ensures a clean slate and avoids issues with template1.

8. Renaming databases in a replication setup in PostgreSQL: In a replication setup, ensure that replication is paused or stopped before renaming the database. Update configurations accordingly.

9. Impact on stored procedures and functions when renaming a database in PostgreSQL: Stored procedures and functions within the database may need to be updated with the new database name.

10. Undoing a database rename in PostgreSQL:

    ALTER DATABASE new_database_name RENAME TO old_database_name;
    

11. Renaming databases and search_path in PostgreSQL: Updating the search_path in affected roles, functions, and stored procedures may be necessary after renaming the database.

12. Renaming databases and schema ownership in PostgreSQL: Verify and update schema ownership after renaming the database to ensure proper functioning of objects.

13. Renaming databases and foreign key relationships in PostgreSQL: Update foreign key references in other databases or within the same database after renaming.

14. Renaming databases and views in PostgreSQL: Update view definitions and dependencies referencing the old database name.

15. Renaming databases and stored procedures in PostgreSQL: Check and update stored procedures using the old database name.

16. Renaming databases and triggers in PostgreSQL: Update trigger definitions and dependencies using the old database name.

17. Renaming databases and roles in PostgreSQL: Update role memberships and permissions associated with the renamed database.