Oracle Database / SQL & PL/SQL Errors
ORA-06502: locate a PL/SQL value or conversion error
A value can exceed a variable's capacity or fail conversion inside PL/SQL even when its source query succeeds. Preserve the full runtime backtrace.
Environment and inputs: Oracle Database 19c baseline · SQL*Plus-compatible SQL unless RMAN, DGMGRL, ADRCI or a host shell is specified. Check release, patch level, edition and container first.
Start with this diagnostic
Use the stated SQL, RMAN, DGMGRL or host shell and replace sample names with approved targets. DBA and V$ views need authorized catalog access in the correct container. Do not grant broad privileges for an example.
SELECT argument_name, data_type, in_out FROM all_arguments WHERE owner = 'APP_OWNER' AND package_name = 'APP_ORDER_API' AND object_name = 'SAVE_ORDER' ORDER BY sequence;Read the result
The signature helps compare caller binds with declared arguments. Local variable sizes and assignments still require source inspection at the failing line.
Resolve and verify
Match the input type, byte or character length and numeric precision to the PL/SQL declaration. Correct the contract and test edge values.
Operational precautions
Do not log private input values or enlarge every variable without understanding the actual conversion failure.