Built-in Functions¶
Nebula Graph supports calling built-in functions of the following types:
Math¶
| Function | Description |
|---|---|
| double abs(double x) | Return absolute value of the argument |
| double floor(double x) | Return the largest integer value smaller than or equal to the argument. (Rounds down) |
| double ceil(double x) | Return the smallest integer greater than or equal to the argument. (Rounds up) |
| double round(double x) | Return integral value nearest to the argument, returns a number farther away from 0 if the parameter is in the middle |
| double sqrt(double x) | Return the square root of the argument |
| double cbrt(double x) | Return the cubic root of the argument |
| double hypot(double x, double y) | Return the hypotenuse of a right-angled triangle |
| double pow(double x, double y) | Compute the power of the argument |
| double exp(double x) | Return the value of e raised to the x power |
| double exp2(double x) | Return 2 raised to the argument |
| double log(double x) | Return natural logarithm of the argument |
| double log2(double x) | Return the base-2 logarithm of the argument |
| double log10(double x) | Return the base-10 logarithm of the argument |
| double sin(double x) | Return sine of the argument |
| double asin(double x) | Return inverse sine of the argument |
| double cos(double x) | Return cosine of the argument |
| double acos(double x) | Return inverse cosine of the argument |
| double tan(double x) | Return tangent of the argument |
| double atan(double x) | Return inverse tangent the argument |
| int rand32() | Return a random 32 bit integer |
| int rand32(int max) | Return a random 32 bit integer in [0, max) |
| int rand32(int min, int max) | Return a random 32 bit integer in [min, max) |
| int rand64() | Return a random 64 bit integer |
| int rand64(int max) | Return a random 64 bit integer in [0, max) |
| int rand64(int min, int max) | Return a random 64 bit integer in [min, max) |
String¶
NOTE: Like SQL, nGQL's character index (location) starts at 1, not like C language from 0.
| Function | Description |
|---|---|
| int strcasecmp(string a, string b) | Compare strings without case sensitivity, when a = b, return 0, when a > b returned value is greater than 0, otherwise less than 0 |
| string lower(string a) | Return the argument in lowercase |
| string upper(string a) | Return the argument in uppercase |
| int length(string a) | Return length (int) of given string in bytes |
| string trim(string a) | Remove leading and trailing spaces |
| string ltrim(string a) | Remove leading spaces |
| string rtrim(string a) | Remove trailing spaces |
| string left(string a, int count) | Return the substring in [1, count], if length a is less than count, return a |
| string right(string a, int count) | Return the substring in [size - count + 1, size], if length a is less than count, return a |
| string lpad(string a, int size, string letters) | Left-pads a string with another string to a certain length |
| string rpad(string a, int size, string letters) | Reft-pads a string with another string to a certain length |
| string substr(string a, int pos, int count) | Extract a substring from a string, starting at the specified position, extract the specified length characters |
| int hash(string a) | Encode the data into integer value |
Explanations on the returns of function substr:
- If pos is 0, return empty string
- If the absolute value of pos is greater than the string, return empty string
- If pos is greater than 0, return substring in [pos, pos + count)
- If pos is less than 0, and set position N as length(a) + pos + 1, return substring in [N, N + count)
- If count is greater than length(a), return the whole string
Timestamp¶
| Function | Description |
|---|---|
| int now() | Return the current date and time |
Last update: April 8, 2021