Categories:

Conversion Functions , Date & Time Functions

TRY_TO_DATE

A special version of TO_DATE , DATE that performs the same operation (i.e. converts an input expression to a date), but with error-handling support (i.e. if the conversion cannot be performed, it returns a NULL value instead of raising an error).

For more information, see Error-handling Conversion Functions.

See also:

TO_DATE , DATE

Syntax

TRY_TO_DATE( <string_expr> [, <format> ] )
TRY_TO_DATE( '<integer>' )

Arguments

Required:

One of:

string_expr

String from which to extract a date, for example ‘2019-01-31’.

integer

An expression that evaluates to a string containing an integer, for example ‘15000000’. Depending upon the magnitude of the string, it can be interpreted as seconds, milliseconds, microseconds, or nanoseconds. For details, see the Usage Notes below.

The use of quoted integers as inputs is deprecated.

Optional:

format

Date format specifier for string_expr or AUTO, which specifies that Snowflake should automatically detect the format to use. For more information, see Date and Time Formats in Conversion Functions.

The default is the current value of the DATE_INPUT_FORMAT session parameter (usually AUTO).

Returns

The data type of the returned value is DATE.

Usage Notes

  • If the format of the input parameter is a string that contains an integer:

    • After the string is converted to an integer, the integer is treated as a number of seconds, milliseconds, microseconds, or nanoseconds after the start of the Unix epoch (1970-01-01 00:00:00.000000000 UTC).

      • If the integer is less than 31536000000 (the number of milliseconds in a year), then the value is treated as a number of seconds.

      • If the value is greater than or equal to 31536000000 and less than 31536000000000, then the value is treated as milliseconds.

      • If the value is greater than or equal to 31536000000000 and less than 31536000000000000, then the value is treated as microseconds.

      • If the value is greater than or equal to 31536000000000000, then the value is treated as nanoseconds.

      Caution

      Currently, negative values are always treated as seconds. For example, -31536000000000000000 is treated as a number of seconds before the year 1970, although its scale implies that it is intended to be used as nanoseconds.

      This behavior might change in the future.

      Caution

      Deprecation Warning: Future versions of Snowflake might automatically interpret stringified integer values as seconds, rather than as milliseconds, microseconds, or nanoseconds. Snowflake recommends that you call TO_DATE, TO_TIME, or TO_TIMESTAMP with strings that contain integers only when those integers are intended to be interpreted as seconds.

    • If more than one row is evaluated (for example, if the input is the column name of a table that contains more than two rows), the first processed value determines whether all subsequent values are treated as seconds, milliseconds, microseconds, or nanoseconds.

      If the first value is greater than or equal to 31536000000, then all values will be treated as milliseconds, even if some remaining values are less than 31536000000. Similar logic applies for microseconds and nanoseconds.

Examples

This demonstrates usage of TRY_TO_DATE:

SELECT TRY_TO_DATE('2018-09-15'), TRY_TO_DATE('Invalid');
+---------------------------+------------------------+
| TRY_TO_DATE('2018-09-15') | TRY_TO_DATE('INVALID') |
|---------------------------+------------------------|
| 2018-09-15                | NULL                   |
+---------------------------+------------------------+