| Function | Effect |
|---|---|
| SUBSTRING | Extracts a substring from a source string |
| SUBSTRING SIMILAR | Extracts a substring from a source string, using POSIX-based regular expressions |
| SUBSTRING_REGEX | Extracts from a string the first occurrence of an XQuery regular expression pattern and returns one occurrence of the matching substring |
| TRANSLATE_REGEX | Extracts from a string the first or every occurrence of an XQuery regular expression pattern and replaces it or them with an XQuery replacement string |
| UPPER | Converts a character string to all uppercase |
| LOWER | Converts a character string to all lowercase |
| TRIM | Trims off leading or trailing blanks |
| TRANSLATE | Transforms a source string from one character set to another |
| CONVERT | Transforms a source string from one character set to another |
| Function | Effect |
|---|---|
| POSITION | Returns the starting position of a target string within a source string |
| CHARACTER_LENGTH | Returns the number of characters in a string |
| OCTET_LENGTH | Returns the number of octets (bytes) in a character string |
| EXTRACT | Extracts a single field from a datetime or interval |
| Function | Effect |
|---|---|
| CURRENT_DATE | Returns the current date |
| CURRENT_TIME(p) | Returns the current time; (p) is precision of seconds |
| CURRENT_TIMESTAMP(p) | Returns the current date and the current time; (p) is precision of seconds |