Functions
This topic lists functions, available in Skyvia.
General Functions
General functions allow you to create NULL values, check column values if they are NULL, and replace NULL values.
Function | Parameters | Description |
---|---|---|
isnull | value - any type | Checks whether the specified value is a NULL value. |
null | no arguments or value argument of any type | Called with no arguments, returns a NULL value. Called with an argument, returns a NULL value of the argument type. |
replace_null | arg1 - any type, arg2 - any type |
If the first argument is not NULL, returns the first argument; otherwise, returns the second argument. |
Data Type Conversion Functions
Data type conversion functions allow converting values from one data type to another. They have overloads without parameters and with a paramter of types, conversion from which is supported. The overloads without parameters return a zero or empty values of the specified type. Thus, bool() returns false, int() or any other numeric type function returns 0, and string() returns an empty string.
Function | Parameters | Description |
---|---|---|
bool | Accepts booloean, string, or numeric values. | If an argument is false or 0, returns false. If an argument is true or a non-zero number, retuns true. It also accepts strings ‘true’ or ‘false’ (case insensitive) or strings that can be converted to a number. Other strings would cause an error. |
currency | Accepts boolean, string, or numeric values. | Converts values to decimal type. |
datetime | Accepts datetime, string, or datetimeoffset values. | Converts values to datetime type. |
datetimeoffset | Accepts datetime, string, datetimeoffset, or int8 values. | Converts values to datetimeoffset type. |
decimal | Accepts boolean, string, or numeric values. | Converts values to decimal type. |
float4 | Accepts boolean, string, or numeric values. | Converts values to float4 type. |
float8 | Accepts boolean, string, or numeric values. | Converts values to float8 type. |
guid | Accepts guid or string values | Converts values to guid type. |
int1 | Accepts boolean, string, or numeric values. | Converts values to int1 type. |
int2 | Accepts boolean, string, or numeric values. | Converts values to int2 type. |
int4 | Accepts boolean, string, or numeric values. | Converts values to int4 type. |
int8 | Accepts boolean, string, or numeric values. | Converts values to int8 type. |
string | Accepts any values | Converts values to strings. |
time | Accepts time, numeric, or string values | Converts values to time type. |
String Functions
String and binary functions perform actions over string values and also encode binary values into strings and vice versa.
Function | Parameters | Description |
---|---|---|
codepoint | input - string | Returns the Unicode code point of the leftmost character of the argument. |
concat | arg1 - string, arg2 - string |
Concatenates two strings. |
decode_base64 | value - string | Converts the specified string, which encodes binary data as base-64 digits, to an equivalent 8-bit unsigned integer array. |
decode_hex | value - string | Converts hex string to byte array. |
encode_base64 | input - bytes | Encodes byte array to base64-encoded string. |
encode_hex | input - bytes | Encodes byte array to hexadecimal string. |
find_string | expression - string, searchString - string, occurrence - int8 |
Returns the 1-based location of the specified occurrence of the search string in the specified string expression. |
hex | expression - int8 | Converts an integer value to its equivalent string representation in hexadecimal format. |
is_null_or_empty | value - string | Checks whether the specified string value is a NULL value or and empty string. |
left | expression - string, number - int8 |
Returns the specified number of characters from the leftmost part of the specified string. |
len | expression - string | Returns the number of characters in the specified string. |
length | expression - bytes | Returns the total number of elements of the byte array. |
lower | expression - string | Returns a copy of the specified string converted to lowercase. |
ltrim | expression - string | Removes all leading white-space characters from the specified string. |
replace | expression - string, searchString - string, replacementString - string |
Replaces all the occurrences of the search string in the expression string with the replacement string. |
replicate | expression - string, times - int8 |
Returns the expression string replicated the specified number of times in the expression string with the replacement string. |
reverse | expression - string | Returns the specified string in reverse order. |
right | expression - string, number - int8 |
Returns the specified number of rightmost characters from the rightmost part of the specified string. |
rtrim | expression - string | Removes all trailing white-space characters from the specified string. |
sha256_encrypt | data - string or bytes, salt - string (base64 encoded) or bytes |
Encrypts the specified data with the salt added as a suffix using SHA-256 algorithm. |
sha512_encrypt | data - string or bytes, salt - string (base64 encoded) or bytes |
Encrypts the specified data with the salt added as a suffix using SHA-512 algorithm. |
substring | expression - string, position - int8, number - int8 |
Returns the specified number of the characters of the expression argument starting from the specified position. |
token | expression - string, delimiter - string, occurrence - int8 |
Returns the specified token in the expression string, divided into tokens by the characters, specified in the delimiter string. |
token_count | expression - string, delimiter - string |
Returns the number of tokens in the expression string, divided into tokens by the characters, specified in the delimiter string. |
trim | expression - string | Removes all leading and trailing white-space characters from the specified string. |
upper | expression - string | Returns a copy of the specified string converted to uppercase. |
You can find some examples of using the string functions in the Examples topic.
Mathematical Functions
Mathematical functions perform various mathematical operations over numeric values. Some of them are analogs of arithmetic operators, like +, -, *, /, %.
Function | Parameters | Description |
---|---|---|
abs | value - any numeric type | Returns the absolute value of an argument. Value has the same type as the argument. |
ceiling | value - decimal or float8 | Returns the smallest integer that is greater than or equal to the argument. |
exp | value - decimal or float8 | Returns an exponent of the argument. |
floor | value - decimal or float8 | Returns the largest integer that is less than or equal to the argument. |
ln | value - decimal or float8 | Returns the natural logarithm of the argument. |
log | value - decimal or float8 | Returns the base-10 logarithm of the argument. |
power | value - decimal or float8 power - decimal or float8 |
Raises the first argument to the power of the second argument. |
round | value - decimal or float8, precision - int4 |
Rounds the value to the specified precision. |
sign | value - any numeric type | If the argument is less than zero, returns -1. If the argument is greater than zero, returns 1. If the argument is zero, returns zero. |
sqrt | value - decimal or float8 | Returns the square root of the argument. |
square | value - decimal or float8 | Returns the square of the argument. |
sub | arg1 - any numeric type, arg2 - any numeric type |
Subtracts the second argument from the first one. |
Datetime Functions
Datetime functions perform actions over datetime values.
Function | Parameters | Description |
---|---|---|
convert_tz | date - datetime, sourceTimezone - string, targetTimezone - string |
Converts the specified date from one timezone to another. See the list of timezones here and examples of using timezones here. Note that you need to pass values from the Timezone ID column of the above list to this function. |
date_add | datepart - string*, number - int8, date - datetime |
Adds the specified number to the specified part of the date. |
date_diff | datepart - string*, startDate - datetime, endDate - datetime |
Returns the number of the datepart interval boundaries, crossed between the specified start and end dates. |
date_format | date - datetime*, format - string |
Converts the specified datetime value to its equivalent string representation using the specified format string. You can use standard or custom datetime format strings. |
date_part | datepart - string*, date - datetime |
Returns an integer, representing the specified datepart of the date. |
day | date - datetime | Returns an integer, representing the day datepart of the date. |
get_date | no parameters | Returns the current date. |
get_utc_date | no parameters | Returns the current date in UTC. |
month | date - datetime | Returns an integer, representing the month datepart of the date. |
year | date - datetime | Returns an integer, representing the year datepart of the date. |
* The datepart argument is a string, specifying the datetime interval. The following table lists the time intervals and corresponding datepart values. Datepart values are case-insensitive.
Interval | Acceptable datepart values |
---|---|
Year | yy, yyyy |
Quarter | qq, q |
Month | mm, m |
Dayofyear | dy, y |
Day | dd, d |
Week | wk, ww |
Weekday | dw |
Hour | hh |
Minute | mi, n |
Second | ss, s |
Millisecond | ms |