DATEDIFF UDF
Description
This UDF is used as a template for all cases when there is a subtraction between a DATE,
TIMESTAMP,
and any other type (except Intervals).
Custom UDF overloads
DATEDIFF_UDF(date, date)
Parameters
FIRST_PARAM: The first
DATE
of the operation.SECOND_PARAM: The
DATE
to be subtracted.
CREATE OR REPLACE FUNCTION PUBLIC.DATEDIFF_UDF(FIRST_PARAM DATE, SECOND_PARAM DATE)
RETURNS INTEGER
LANGUAGE SQL
IMMUTABLE
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"udf"}}'
AS
$$
FIRST_PARAM - SECOND_PARAM
$$;
DATEDIFF_UDF(date, timestamp)
Parameters
FIRST_PARAM: The first
DATE
of the operation.SECOND_PARAM: The
TIMESTAMP
to be subtracted.
CREATE OR REPLACE FUNCTION PUBLIC.DATEDIFF_UDF(FIRST_PARAM DATE, SECOND_PARAM TIMESTAMP)
RETURNS INTEGER
LANGUAGE SQL
IMMUTABLE
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"udf"}}'
AS
$$
FIRST_PARAM - SECOND_PARAM::DATE
$$;
DATEDIFF_UDF(date, integer)
Parameters
FIRST_PARAM: The first
DATE
of the operation.SECOND_PARAM: The
INTEGER
to be subtracted.
CREATE OR REPLACE FUNCTION PUBLIC.DATEDIFF_UDF(FIRST_PARAM DATE, SECOND_PARAM INTEGER)
RETURNS DATE
LANGUAGE SQL
IMMUTABLE
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"udf"}}'
AS
$$
DATEADD(day,SECOND_PARAM*-1 ,FIRST_PARAM)
$$;
DATEDIFF_UDF(timestamp, timestamp)
Parameters
FIRST_PARAM: The first
TIMESTAMP
of the operation.SECOND_PARAM: The
TIMESTAMP
to be subtracted.
CREATE OR REPLACE FUNCTION PUBLIC.DATEDIFF_UDF(FIRST_PARAM TIMESTAMP, SECOND_PARAM TIMESTAMP)
RETURNS INTEGER
LANGUAGE SQL
IMMUTABLE
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"udf"}}'
AS
$$
DATEDIFF(day,SECOND_PARAM ,FIRST_PARAM)
$$;
DATEDIFF_UDF(timestamp, date)
Parameters
FIRST_PARAM: The first
TIMESTAMP
of the operation.SECOND_PARAM: The
DATE
to be subtracted.
CREATE OR REPLACE FUNCTION PUBLIC.DATEDIFF_UDF(FIRST_PARAM TIMESTAMP, SECOND_PARAM DATE)
RETURNS INTEGER
LANGUAGE SQL
IMMUTABLE
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"udf"}}'
AS
$$
DATEDIFF(day,SECOND_PARAM ,FIRST_PARAM)
$$;
DATEDIFF_UDF(timestamp, number)
Parameters
FIRST_PARAM: The first
TIMESTAMP
of the operation.SECOND_PARAM: The
NUMBER
to be subtracted.
CREATE OR REPLACE FUNCTION PUBLIC.DATEDIFF_UDF(FIRST_PARAM TIMESTAMP, SECOND_PARAM NUMBER)
RETURNS TIMESTAMP
LANGUAGE SQL
IMMUTABLE
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"udf"}}'
AS
$$
DATEADD(day,SECOND_PARAM*-1,FIRST_PARAM)
$$;
Usage example
--disableDateAsTimestamp
--disableDateAsTimestamp
Flag to indicate whether SYSDATE
should be transformed into CURRENT_DATE
or CURRENT_TIMESTAMP
. This will also affect all DATE
columns that will be transformed to TIMESTAMP
.
Oracle
--Create Table
CREATE TABLE times(AsTimeStamp TIMESTAMP, AsDate DATE);
--Subtraction operations
SELECT AsDate - unknown FROM times, unknown_table;
SELECT unknown - AsTimeStamp FROM times;
SELECT AsTimeStamp - unknown FROM times;
SELECT unknown - AsDate FROM times;
Snowflake
--Create Table
CREATE OR REPLACE TABLE times (AsTimeStamp TIMESTAMP(6),
AsDate TIMESTAMP
)
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
;
--Subtraction operations
SELECT
PUBLIC.DATEDIFF_UDF(
!!!RESOLVE EWI!!! /*** SSC-EWI-OR0036 - TYPES RESOLUTION ISSUES, ARITHMETIC OPERATION '-' MAY NOT BEHAVE CORRECTLY BETWEEN DATE AND unknown ***/!!!
AsDate,
unknown
)
FROM
times,
unknown_table;
SELECT
PUBLIC.DATEDIFF_UDF(
!!!RESOLVE EWI!!! /*** SSC-EWI-OR0036 - TYPES RESOLUTION ISSUES, ARITHMETIC OPERATION '-' MAY NOT BEHAVE CORRECTLY BETWEEN unknown AND Timestamp ***/!!!
unknown,
AsTimeStamp
)
FROM
times;
SELECT
PUBLIC.DATEDIFF_UDF(
!!!RESOLVE EWI!!! /*** SSC-EWI-OR0036 - TYPES RESOLUTION ISSUES, ARITHMETIC OPERATION '-' MAY NOT BEHAVE CORRECTLY BETWEEN Timestamp AND unknown ***/!!!
AsTimeStamp,
unknown
)
FROM
times;
SELECT
PUBLIC.DATEDIFF_UDF(
!!!RESOLVE EWI!!! /*** SSC-EWI-OR0036 - TYPES RESOLUTION ISSUES, ARITHMETIC OPERATION '-' MAY NOT BEHAVE CORRECTLY BETWEEN unknown AND DATE ***/!!!
unknown,
AsDate
)
FROM
times;
Known Issues
1. Functional differences for timestamps
Sometimes the Snowflake value returned by the UDF may differ from the Oracle one due to the time. Consider the following example
Oracle
-- CREATE TABLE UNKNOWN_TABLE(Unknown timestamp);
-- INSERT INTO UNKNOWN_TABLE VALUES (TO_TIMESTAMP('01/10/09, 12:00 P.M.', 'dd/mm/yy, hh:mi P.M.'));
CREATE TABLE TIMES(AsTimeStamp TIMESTAMP);
INSERT INTO TIMES VALUES (TO_TIMESTAMP('05/11/21, 11:00 A.M.', 'dd/mm/yy, hh:mi A.M.'));
SELECT AsTimeStamp - unknown FROM times, unknown_table;
Snowflake
-- CREATE TABLE UNKNOWN_TABLE(Unknown timestamp);
-- INSERT INTO UNKNOWN_TABLE VALUES (TO_TIMESTAMP('01/10/09, 12:00 P.M.', 'dd/mm/yy, hh:mi P.M.'));
CREATE OR REPLACE TABLE TIMES (AsTimeStamp TIMESTAMP(6)
)
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
;
INSERT INTO TIMES
VALUES (TO_TIMESTAMP('05/11/21, 11:00 A.M.', 'dd/mm/yy, hh:mi A.M.'));
SELECT
PUBLIC.DATEDIFF_UDF(
!!!RESOLVE EWI!!! /*** SSC-EWI-OR0036 - TYPES RESOLUTION ISSUES, ARITHMETIC OPERATION '-' MAY NOT BEHAVE CORRECTLY BETWEEN Timestamp AND unknown ***/!!!
AsTimeStamp,
unknown
)
FROM
times,
unknown_table;
Related EWIs
SSC-EWI-OR0036: Types resolution issues, the arithmetic operation may not behave correctly between string and date.
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