MySQL CONV() Function

MySQL CONV() Function: Numeric/System Operations

The MySQL CONV() function converts numbers between different number bases (e.g. base 10 to base 16). It allows developers to perform deterministic data transformations directly within SQL queries.

Key Characteristics and Usage

• Category: MySQL Numeric/System Function
• Return Data Type: VARCHAR
• NULL Safety: Returns NULL if any required input argument evaluates to NULL.

Function Parameters

• Parameters: number, from_base, to_base

Practical SQL Code Example

-- Query demonstrating MySQL CONV() usage in production queries
SELECT CONV(15, 10, 16) AS hex_val;

Expected Output

Best Practices & Common Gotchas

• NULL Value Handling: Always wrap function calls in IFNULL() or COALESCE() if your input columns allow NULL values.
• Index Usage: Using scalar functions directly on indexed columns in WHERE clauses disables B-tree index lookups (causing full table scans). Use generated columns with indexes when querying heavily.
• Type Compatibility: Ensure input argument data types match expected function inputs to avoid silent implicit conversions.

Self-Check Challenge

Write a SQL query using CONV() to format or evaluate data retrieved from a database table.