Maxcompute string splitting function -split_ PART

Grammar format

string split_part(string <str>, string <separator>, bigint <start>[, bigint <end>])

Function description

According to the separator separator Split string str, Return from start Part to end Substring of part （ Closed interval ）.

Parameter description

• str： Required .STRING type . The string to be split . If it is BIGINT、DOUBLE、DECIMAL or DATETIME type , Will be implicitly converted to STRING Participate in the operation after type .
• separator： Required .STRING Type constant . Separator for splitting , It can be a character , It can also be a string .
• start： Required .BIGINT Type constant , Must be greater than 0. Indicates the start number of the returned segment （ from 1 Start ）.
• end：BIGINT Type constant , Greater than or equal to start. Indicates the end number of the returned segment , Omission , By default, it means and start The values are equal , return start Specified segment .

Return value description

return STRING type . The return rule is as follows ：

• If start The value of is greater than the actual number of segments after segmentation , For example, there is 6 A fragment ,start Greater than 6, Return to empty string .
• If separator There is no in str in , And start Designated as 1, Back to the whole str. If str For the empty string , Then an empty string is output .
• If separator For the empty string , Return the original string str.
• If end Greater than the number of fragments , Return from start The starting substring .
• str Not STRING、BIGINT、DOUBLE、DECIMAL or DATETIME Type , Return error .
• separator Not STRING Type constant , Return error .
• start or end Not BIGINT Type constant , Return error .
• except separator Outside , If any parameter value is NULL, return NULL.

Examples of use

Example 1： According to the separator , Split string a,b,c,d, Returns the substring of the specified part . An example command is as follows .

-- return a.
select split_part('a,b,c,d', ',', 1);
-- return a,b.
select split_part('a,b,c,d', ',', 1, 2);

Example 2：start The value of is greater than the actual number of segments after segmentation . An example command is as follows .

-- Return to empty string .
select split_part('a,b,c,d', ',', 10);

Example 3：separator There is no in str in . An example command is as follows .

-- return a,b,c,d.
select split_part('a,b,c,d', ':', 1);
-- Return to empty string .
select split_part('a,b,c,d', ':', 2);

Example 4：separator For the empty string . An example command is as follows .

-- return a,b,c,d.
select split_part('a,b,c,d', '', 1);

Example 5：end The value of is greater than the actual number of segments after segmentation . An example command is as follows .

-- return b,c,d.
select split_part('a,b,c,d', ',', 2, 6);

Example 6： except separator Outside , Any input parameter is NULL. An example command is as follows .

-- return NULL.
select split_part('a,b,c,d', ',', null);