PostgreSQL SELECT
The SELECT statement retrieves data from one or more tables in PostgreSQL. It is the most commonly used SQL command for querying data.
Key Topics
1. Basic SELECT Syntax
SELECT *
FROM table_name;
This retrieves all columns and rows from the specified table.
2. Selecting Specific Columns
SELECT column1, column2
FROM table_name;
Only the listed columns are returned, which is more efficient than selecting all columns.
Best Practices
- Use specific column names instead of
*to improve query performance and clarity. - Leverage indexing on frequently queried columns for faster data retrieval.
Key Takeaways
SELECTis fundamental for data retrieval in PostgreSQL.- Specifying columns reduces overhead and improves readability.