Conversion
Conversion functions
Trino will implicitly convert numeric and character values to the correct type if such a conversion is possible. Trino will not convert between character and numeric types. For example, a query that expects a varchar will not automatically convert a bigint value to an equivalent varchar.
When necessary, values can be explicitly cast to a particular type.
Conversion functions
cast
cast(value AS type) -> type
Explicitly cast a value as a type. This can be used to cast a varchar to a numeric value type and vice versa.
try_cast
try_cast(value AS type) -> type
Like cast, but returns null if the cast fails.
Formatting
format
format(format, args...) -> varchar
Returns a formatted string using the specified format string and arguments:
SELECT format('%s%%', 123);
-- '123%'
SELECT format('%.5f', pi());
-- '3.14159'
SELECT format('%03d', 8);
-- '008'
SELECT format('%,.2f', 1234567.89);
-- '1,234,567.89'
SELECT format('%-7s,%7s', 'hello', 'world');
-- 'hello , world'
SELECT format('%2$s %3$s %1$s', 'a', 'b', 'c');
-- 'b c a'
SELECT format('%1$tA, %1$tB %1$te, %1$tY', date '2006-07-04');
-- 'Tuesday, July 4, 2006'
format_number
format_number(number) -> varchar
Returns a formatted string using a unit symbol:
SELECT format_number(123456); -- '123K'
SELECT format_number(1000000); -- '1M'
Data size
The parse_data_size
function supports the following units:
Unit | Description | Value |
---|---|---|
B | Bytes | 1 |
kB | Kilobytes | 1024 |
MB | Megabytes | 10242 |
GB | Gigabytes | 10243 |
TB | Terabytes | 10244 |
PB | Petabytes | 10245 |
EB | Exabytes | 10246 |
ZB | Zettabytes | 10247 |
YB | Yottabytes | 10248 |
parse_data_size
parse_data_size(string) -> decimal(38)
Parses string
of format value unit
into a number, where
value
is the fractional number of unit
values:
SELECT parse_data_size('1B'); -- 1
SELECT parse_data_size('1kB'); -- 1024
SELECT parse_data_size('1MB'); -- 1048576
SELECT parse_data_size('2.3MB'); -- 2411724
Miscellaneous
typeof
typeof(expr) -> varchar
Returns the name of the type of the provided expression:
SELECT typeof(123); -- integer
SELECT typeof('cat'); -- varchar(3)
SELECT typeof(cos(2) + 1.5); -- double