split_part¶
This function is used to split a specified string based on a specified separator and return a substring from the start to end position.
Syntax¶
split_part(string <str>, string <separator>, bigint <start>[, bigint <end>])
Parameters¶
Parameter | Mandatory | Type | Description |
|---|---|---|---|
str | Yes | STRING | String to be split |
separator | Yes | STRING | Constant of the STRING type. Separator used for splitting. The value can be a character or a string. |
start | Yes | STRING | Constant of the BIGINT type. The value must be greater than 0. Start number of the returned part, starting from 1. |
end | No | BIGINT | Constant of the BIGINT type. The value must be greater than or equal to the value of start. End number of the returned part and can be omitted. The default value indicates that the value is the same as that of start, and the part specified by start is returned. |
Return Values¶
The return value is of the STRING type.
Note
If the value of start is greater than the actual number of segments after splitting, for example, if there are four segments after string splitting and the value of start is greater than 4, an empty string is returned.
If separator does not exist in str and start is set to 1, the entire str is returned. If the value of str is an empty string, an empty string is output.
If the value of separator is an empty string, the original string str is returned.
If the value of end is greater than the number of segments, the substring starting from start is returned.
If the value of str is not of the STRING, BIGINT, DOUBLE, DECIMAL, or DATETIME type, an error is reported.
If the value of start or end is not a constant of the BIGINT type, an error is reported.
If the value of any parameter except separator is NULL, NULL is returned.
Example Code¶
The value aa is returned.
select split_part('aa,bb,cc,dd', ',', 1);
The value aa,bb is returned.
select split_part('aa,bb,cc,dd', ',', 1, 2);
An empty string is returned.
select split_part('aa,bb,cc,dd', ',', 10);
The value aa,bb,cc,dd is returned.
select split_part('aa,bb,cc,dd', ':', 1);
An empty string is returned.
select split_part('aa,bb,cc,dd', ':', 2);
The value aa,bb,cc,dd is returned.
select split_part('aa,bb,cc,dd', '', 1);
The value bb,cc,dd is returned.
select split_part('aa,bb,cc,dd', ',', 2, 6);
The value NULL is returned.
select split_part('aa,bb,cc,dd', ',', null);