What causes WRONG_NUM_ARGS?

Calling a built-in function with too few or too many arguments, e.g. `DATE_TRUNC()` missing the unit argument. Invoking a user-defined function (UDF) or registered function with an incorrect number of parameters. Copy-paste errors when adapting SQL from another dialect (MySQL, PostgreSQL) where argument order or count differs. Macro or templated SQL generating a function call with a variable-length argument list that evaluates to the wrong count. Calling `COALESCE` or `GREATEST` with zero arguments

How do I fix WRONG_NUM_ARGS?

Check the official Databricks function reference for the correct signature. Run `DESCRIBE FUNCTION EXTENDED ` in a SQL warehouse to see the expected argument list. If using a UDF, review the Python/Scala function definition for the expected parameter count. Update templated SQL to ensure all variable expansions produce the correct number of arguments. Compare the function name against equivalent functions in other SQL dialects to catch naming/signature differences

Low severityquery

Power BI Refresh Error:
WRONG_NUM_ARGS

What does this error mean?

A function call was made with the wrong number of arguments. Spark SQL validates argument counts at parse time and rejects queries that do not match the function signature.

Common causes

1Calling a built-in function with too few or too many arguments, e.g. `DATE_TRUNC()` missing the unit argument
2Invoking a user-defined function (UDF) or registered function with an incorrect number of parameters
3Copy-paste errors when adapting SQL from another dialect (MySQL, PostgreSQL) where argument order or count differs
4Macro or templated SQL generating a function call with a variable-length argument list that evaluates to the wrong count
5Calling `COALESCE` or `GREATEST` with zero arguments

How to fix it

1Check the official Databricks function reference for the correct signature
2Run `DESCRIBE FUNCTION EXTENDED <function_name>` in a SQL warehouse to see the expected argument list
3If using a UDF, review the Python/Scala function definition for the expected parameter count
4Update templated SQL to ensure all variable expansions produce the correct number of arguments
5Compare the function name against equivalent functions in other SQL dialects to catch naming/signature differences

Frequently asked questions

How do I look up a Databricks built-in function signature?

Run `DESCRIBE FUNCTION EXTENDED <function_name>` in a SQL warehouse or notebook. It returns the full signature, description, and examples.