The database engine raises this arithmetic runtime error when an expression attempts to divide a numeric value by zero.
Division by zero error occurs when a SQL expression attempts to divide a number by 0. Fix it by validating denominators with NULLIF, CASE, or CHECK constraints before division.
SQL Server: Divide by zero error encountered. PostgreSQL: ERROR: division by zero MySQL: ERROR 1365 (22012): Division by 0
Division by zero is an arithmetic runtime error thrown by every major SQL engine when an expression divides a numeric value by 0 or by a NULL that evaluates to 0. The database aborts the statement, returns an error code, and may roll back the current transaction.
Because division is undefined for zero, the engine blocks execution to protect data integrity.
Unhandled, this error breaks dashboards, APIs, and background jobs, so identifying and patching it quickly is critical for high-availability systems.
An explicit constant 0 in a denominator immediately triggers the error: SELECT 1/0 fails in any engine.
Dynamic expressions that resolve to 0, such as SUM(col_b) where all values are zero, also cause the fault at run time.
NULL values treated as 0 by the engine, especially in SQL Server’s SET ANSI_WARNINGS OFF mode, can unexpectedly raise the exception.
User-supplied parameters, division inside calculated columns, and aggregate reports are common contexts where unchecked 0 values slip through.
Validate the denominator before performing division.
The most portable fix is to wrap the denominator with NULLIF; if the value is 0, NULLIF returns NULL and the result becomes NULL instead of error.
Use CASE expressions to return 0, NULL, or an alternate value when the denominator equals 0.
Add CHECK constraints or triggers that disallow zero in columns used as divisors, catching bad data at write time instead of query time.
For reporting queries, aggregate denominators separately and filter out zero rows before joining or selecting.
Percentage calculations often divide by a total count.
Guard with NULLIF(total,0) to avoid failures when no rows exist.
Financial ratios like gross_margin / revenue crash when revenue is 0. Apply CASE WHEN revenue=0 THEN 0 END logic.
Derived metrics in views may hide the division.
Update the view’s SELECT to include protective NULLIF or CASE logic and redeploy.
Stored procedures that accept parameters must validate input: IF @denominator = 0 THROW 50000, 'Division by zero',1;
Never rely on implicit data quality; enforce domain rules with CHECK constraints that forbid 0 in divisor columns.
Use COALESCE(NULLIF(denominator,0),1) only when a fallback of 1 makes mathematical sense; document assumptions clearly.
Create unit tests that run representative queries with edge cases, including zero and NULL, and fail the pipeline on error.
Leverage Galaxy’s AI Copilot to scan new SQL for potential division by zero, suggesting NULLIF wrappers during code review.
Numeric overflow occurs when a result exceeds the data type range; fix by widening types or using TRY_CONVERT.
Invalid cast errors surface when dividing integers and storing in an INT; cast to DECIMAL to preserve precision.
NULL value errors differ because they stem from missing data, not arithmetic impossibility; handle with COALESCE.
In SQL Server you can set SET ARITHABORT OFF or SET ANSI_WARNINGS OFF, but this is discouraged because it replaces the error with NULL and masks bugs.
NULLIF returns NULL when its two arguments match. When the denominator becomes NULL the engine returns NULL instead of attempting an illegal division.
No. The SQL standard defines division by zero as an exception; every compliant engine must raise an error or return NULL in compatibility modes.
Galaxy’s AI Copilot flags risky denominators while you type and suggests NULLIF or CASE fixes, reducing runtime errors before code reaches production.
.png)
.avif){kind=logo}
