See below.Įquivalent, less explicit short syntax: SELECT day::dateįROM generate_series(timestamp '', '', '1 day') day And you do not needlessly involve DST (daylight saving time) rules coupled with the conversion from date to timestamp with time zone and back. The advantage in performance is small, but there is no reason not to take it. Au contraire, timestamp is the best choice. The cast to date ( day::date) does that implicitly.īut there is also no point in casting date literals to date as input parameter. In this tutorial, you have learned how to use the PostgreSQL TO_TIMESTAMP() function to convert a string to a timestamp.To generate a series of dates this is the optimal way: SELECT t.day::dateĪdditional date_trunc() is not needed. The nearest year of 16 is 2016, therefore, it returns the following result: to_timestamp -Ģ016 -12-31 00 :45 :00-07 Code language: CSS ( css ) TO_TIMESTAMP( '12 31 16 12:45', 'MM DD YY HH:MI') Code language: JavaScript ( javascript ) TO_TIMESTAMP( '12 31 99 12:45', 'MM DD YY HH:MI') Code language: JavaScript ( javascript ) ![]() In this case, 002 is interpreted as 0.002 seconds, which is equivalent to 2 milliseconds.Ĥ) If the year is less than four digits, the TO_TIMESTAMP() will adjust it to the nearest year e.g., 99 becomes 1999, 17 becomes 2017. 00:00:10.2-07 Code language: Shell Session ( shell ) In this example, 2 is not 2 millisecond but 200. ![]() TO_TIMESTAMP( '01-01-2017 10:2', 'DD-MM-YYYY SS:MS') Code language: JavaScript ( javascript ) SQL state: 22008 Code language: Shell Session ( shell )ģ) When converting a string to a timestamp, the TO_TIMESTAMP() function treats milliseconds or microseconds as seconds after the decimal point. It returns an error: ERROR: date/time field value out of range: " 30:8:00" TO_TIMESTAMP( ' 30:8:00', 'YYYY-MM-DD HH24:MI:SS') Code language: JavaScript ( javascript ) The following example uses an invalid timestamp value: SELECT It will try to convert the input string to a valid timestamp as much as possible that sometimes yields unexpected results. SQL state: 22007 Code language: Shell Session ( shell )īecause the FX option instructs the TO_TIMESTAMP() to accept the input string with one space only.Ģ) The TO_TIMESTAMP() function validates the input string with minimal error checking. Output: ERROR: invalid value "" for "MON"ĭETAIL: The given value did not match any of the allowed values for this field. TO_TIMESTAMP( '2017 Aug', 'FXYYYY MON') Code language: JavaScript ( javascript ) However, the following example returns an error: SELECT The TO_TIMESTAMP() function just omits the spaces and returns the correct timestamp value: to_timestamp. TO_TIMESTAMP( '2017 Aug', 'YYYY MON') Code language: JavaScript ( javascript ) This example uses multiple spaces in the input string: SELECT Output: to_timestamp -ġ) The TO_TIMESTAMP() function skips spaces in the input string unless the fixed format global option ( FX prefix) is used. ) Code language: SQL (Structured Query Language) ( sql ) The following statement uses the TO_TIMESTAMP() function to convert a string to a timestamp: SELECT TO_TIMESTAMP( The PostgreSQL TO_TIMESTAMP() function returns a timestamp with time zone. Month in lowercase Roman numerals (i-xii > Month in upper case Roman numerals (I-XII > Julian Day (integer days since NovemBC at midnight UTC) Week number of ISO 8601 week-numbering year (01-53 the first Thursday of the year is in week 1) Week number of year (1-53) (the first week starts on the first day of the year) Week of month (1-5) (the first week starts on the first day of the month) ISO 8601 day of the week, Monday (1) to Sunday (7) Last digit of ISO 8601 week-numbering yearĪbbreviated uppercase month name e.g., JAN, FEB, etc.Ībbreviated capitalized month name e.g, Jan, Feb, etc.Ībbreviated lowercase month name e.g., jan, feb, etc.ĭay of ISO 8601 week-numbering year (001-371 day 1 of the year is Monday of the first ISO week)ĭay of the week, Sunday (1) to Saturday (7) Last 2 digits of ISO 8601 week-numbering year Last 3 digits of ISO 8601 week-numbering year ISO 8601 week-numbering year (4 or more digits) ![]() To construct format strings, you use the following template patterns for formatting date and time values. The timestamp is a string that represents a timestamp value in the format specified by format. The TO_TIMESTAMP() function requires two arguments: The following illustrates the syntax of TO_TIMESTAMP() function: TO_TIMESTAMP(timestamp, format) Arguments The PostgreSQL TO_TIMESTAMP() function converts a string to a timestamp according to the specified format. Summary: in this tutorial, you will learn how to use the PostgreSQL TO_TIMESTAMP() function to convert a string to a timestamp based on a specified format
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