These SQL value functions perform operations on data. There are all kinds of operations that could conceivably be performed on data items, but these are some that are needed most often.
String Value Functions
| 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 |
Numeric Value Functions
| 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 |
Datetime Value Functions
| 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 |
Share This
