TryMakeInterval¶

Overview¶

The TryMakeInterval expression creates an interval from separate components (years, months, weeks, days, hours, minutes, seconds). Unlike MakeInterval, this expression returns NULL instead of throwing an exception when an error occurs during interval creation. It is implemented as a RuntimeReplaceable expression that delegates to MakeInterval with failOnError = false.

Syntax¶

try_make_interval([years [, months [, weeks [, days [, hours [, mins [, secs]]]]]]])

Arguments¶

Argument	Type	Description
years	Expression	Number of years (optional, defaults to 0)
months	Expression	Number of months (optional, defaults to 0)
weeks	Expression	Number of weeks (optional, defaults to 0)
days	Expression	Number of days (optional, defaults to 0)
hours	Expression	Number of hours (optional, defaults to 0)
mins	Expression	Number of minutes (optional, defaults to 0)
secs	Expression	Number of seconds as Decimal (optional, defaults to 0)

Return Type¶

Returns INTERVAL data type or NULL if an error occurs during interval construction.

Supported Data Types¶

Numeric types: All numeric expressions are supported for input parameters
Decimal: The seconds parameter specifically uses Decimal type with MAX_LONG_DIGITS precision and scale of 6
Integer literals: Default values use integer literals (0) for most parameters

Algorithm¶

Validates and converts input expressions to appropriate numeric types
Delegates actual interval creation to the underlying MakeInterval expression
Sets failOnError = false to ensure NULL return instead of exceptions
Uses RuntimeReplaceable pattern for expression rewriting during analysis
Supports variable number of arguments through constructor overloading

Partitioning Behavior¶

Preserves partitioning: This expression operates on individual rows and does not require data movement
No shuffle required: Row-level computation that maintains existing data distribution
Deterministic: Given the same inputs, always produces the same output

Edge Cases¶

Null handling: Returns NULL if any input parameter is NULL
Invalid intervals: Returns NULL instead of throwing exceptions for invalid interval combinations
Overflow conditions: Returns NULL when interval components exceed valid ranges
Missing parameters: Automatically fills missing parameters with appropriate zero values (Literal(0) for most, Decimal(0) for seconds)
Empty constructor: Intentionally not supported in try version as it would never overflow

Code Generation¶

This expression supports Tungsten code generation through its RuntimeReplaceable implementation. The expression is replaced with MakeInterval during analysis phase, which then benefits from the underlying MakeInterval code generation capabilities.

Examples¶

-- Create interval with all components
SELECT try_make_interval(1, 2, 3, 4, 5, 6, 7.5);

-- Create interval with partial components
SELECT try_make_interval(2, 3);

-- Handle invalid input gracefully (returns NULL)
SELECT try_make_interval(9999999, 9999999, 9999999);

-- Compare with make_interval behavior
SELECT 
  try_make_interval(1, NULL, 3) as safe_result,  -- Returns NULL
  make_interval(1, NULL, 3) as unsafe_result;    -- Throws exception

// DataFrame API usage
import org.apache.spark.sql.functions._

// Create interval column
df.select(try_make_interval(col("years"), col("months"), col("days")))

// With literal values
df.select(try_make_interval(lit(1), lit(6), lit(0), lit(15)))

// Handle potentially invalid data
df.select(try_make_interval(col("user_years"), col("user_months")))
  .filter(col("interval_col").isNotNull)