SUBSTRING

SUBSTRING()

Substring() extracts a substring from the given string, starting at the specified start index and with the specified length.

Syntax

substring(expr,startIndex,length)

Arguments

expr The input string from which to extract the substring. The argument expr is any expression of type string.

startIndex The starting index of the substring in the evaluated expression, starting at zero. startIndex can be any expression of type int

length (optional) (Default: end of evaluated expr) The length of the substring to extract. length can be any expression of type int.

Return Type

string

Return Value

substring() returns the extracted substring

Remarks

None

Examples

A. Substring of the string in a column

create table segments
    (_id id, segment string);

insert into segments(_id,segment)
    values (1,'green')

select _id, substring(segment,0,3) as substr from segments;
+-----+----------+
| _id | substr   |
+-----+----------+
|   1 | gre      |
+-----+----------+

B. Substring of a reversed string.

create table segments
    (_id id, segment string);

insert into segments(_id,segment)
    values (1,'red')

select _id, substring(reverse(segment), 1) as substr from segments;
+-----+----------+
| _id | substr   |
+-----+----------+
|   1 | er       |
+-----+----------+