TryMakeTimestampFromDateTime¶

Overview¶

TryMakeTimestampFromDateTime is a runtime-replaceable Catalyst expression that attempts to construct a timestamp from date and optional time components. Unlike its non-try counterpart, this expression returns null instead of throwing an exception when the input values cannot be converted to a valid timestamp.

Syntax¶

try_make_timestamp(date [, time] [, timezone])

// DataFrame API usage would depend on the function registry
col("date_col").expr("try_make_timestamp(date_col)")

Arguments¶

Argument	Type	Description
date	Expression	The date component for the timestamp
time	Expression (optional)	The time component to combine with the date
timezone	Expression (optional)	The timezone for the resulting timestamp
replacement	Expression	Internal replacement expression used during runtime

Return Type¶

Returns TimestampType on successful conversion, or null if the conversion fails.

Supported Data Types¶

date: Date types, string representations of dates
time: Time types, string representations of time
timezone: String representations of valid timezone identifiers

Algorithm¶

Delegates evaluation to the underlying MakeTimestampFromDateTime expression through runtime replacement
Catches any exceptions thrown during timestamp construction and returns null instead
Validates that the date component is not null before attempting conversion
Applies timezone conversion if a timezone parameter is provided
Returns the constructed timestamp as a long value representing microseconds since epoch

Partitioning Behavior¶

This expression preserves partitioning behavior:

Does not require data shuffle as it operates row-by-row
Maintains existing partition boundaries
Can be safely pushed down in query optimization

Edge Cases¶

Null date input: Returns null without attempting conversion
Invalid date formats: Returns null instead of throwing parse exceptions
Invalid timezone: Returns null for unrecognized timezone identifiers
Leap second handling: Behavior depends on the underlying datetime implementation
Daylight saving transitions: May return null for ambiguous times during DST changes

Code Generation¶

As a RuntimeReplaceable expression, this delegates code generation to its replacement expression (MakeTimestampFromDateTime). The actual code generation support depends on the underlying replacement implementation.

Examples¶

-- Basic usage with date only
SELECT try_make_timestamp('2023-12-25') as christmas_timestamp;

-- With date and time components  
SELECT try_make_timestamp('2023-12-25', '15:30:00') as afternoon_timestamp;

-- With timezone specification
SELECT try_make_timestamp('2023-12-25', '15:30:00', 'UTC') as utc_timestamp;

-- Handling invalid input (returns null)
SELECT try_make_timestamp('invalid-date') as null_result;

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

df.select(expr("try_make_timestamp(date_col)").as("timestamp_col"))
df.select(expr("try_make_timestamp(date_col, time_col, 'PST')").as("pst_timestamp"))