# KSQL - Add new field to existing struct
**URL:** https://forum.confluent.io/t/ksql-add-new-field-to-existing-struct/1030
**Category:** ksqlDB
**Created:** [25 February 2021 10:28 UTC](https://forum.confluent.io/t/ksql-add-new-field-to-existing-struct/1030 "2021-02-25T10:28:38Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@harinath-sirigiri](https://forum.confluent.io/u/harinath-sirigiri)
#### Post date: [25 February 2021 10:28 UTC](https://forum.confluent.io/t/ksql-add-new-field-to-existing-struct/1030/1 "2021-02-25T10:28:38Z")
A stream contains struct and a string field
```auto
ksql> select * from t_accnt emit changes;
+----------------------------------------------+----------------------------------------------+
|ACCOUNT |OPERATION |
+----------------------------------------------+----------------------------------------------+
|{ACCNT_ID=1234, A1=10, A2=20, A3=30, A4=40} |null |
|{ACCNT_ID=1234, A1=10, A2=20, A3=30, A4=40} |update |
```
I want to achieve the below output in KSQL, basically adding a new field to existing structure (or create new structure)
```auto
{ACCNT_ID=1234, A1=10, A2=20, A3=30, A4=40,OPERATION=update}
```
---
### Author:  [@rmoff](https://forum.confluent.io/u/rmoff)
#### Post date: [25 February 2021 13:32 UTC](https://forum.confluent.io/t/ksql-add-new-field-to-existing-struct/1030/2 "2021-02-25T13:32:58Z")
Here’s one way to do it, although it’s not particularly elegant:
```sql
-- Set up test stream
CREATE STREAM TMP (ACCOUNT STRUCT,
OPERATION VARCHAR)
WITH (KAFKA_TOPIC='test', FORMAT='JSON', PARTITIONS=1);
INSERT INTO TMP VALUES (STRUCT(ID:=1,A1:=2,A2:=3),'UPDATE');
INSERT INTO TMP VALUES (STRUCT(ID:=2,A1:=22,A2:=23),'INSERT');
-- Query data
ksql> SELECT * FROM TMP EMIT CHANGES LIMIT 2;
+----------------------+----------+
|ACCOUNT |OPERATION |
+----------------------+----------+
|{ID=1, A1=2, A2=3} |UPDATE |
|{ID=2, A1=22, A2=23} |INSERT |
Limit Reached
Query terminated
-- Add `OPERATION` into `ACCOUNT` struct
ksql> SELECT STRUCT("ID":=ACCOUNT->ID,
"A1":=ACCOUNT->A1,
"A2":=ACCOUNT->A2,
"OPERATION":=OPERATION) AS ACCOUNT
FROM TMP
EMIT CHANGES LIMIT 2;
+---------------------------------------+
|ACCOUNT |
+---------------------------------------+
|{ID=1, A1=2, A2=3, OPERATION=UPDATE} |
|{ID=2, A1=22, A2=23, OPERATION=INSERT} |
Limit Reached
Query terminated
```
---
### Author:  [@harinath-sirigiri](https://forum.confluent.io/u/harinath-sirigiri)
#### Post date: [25 February 2021 14:25 UTC](https://forum.confluent.io/t/ksql-add-new-field-to-existing-struct/1030/3 "2021-02-25T14:25:28Z")
Hi Robin,
Thank you very much for this , Actually I already tried this forming new struct with limited source struct fields but in my real case i have 50+ fields in source struct and may schema change in future.
Is there any way to explode source struct like ACCNT-\>\* which helps easy to from new struct
Any other alternative /suggestion apart from UDF for this.
---
### Author:  [@rmoff](https://forum.confluent.io/u/rmoff)
#### Post date: [25 February 2021 15:57 UTC](https://forum.confluent.io/t/ksql-add-new-field-to-existing-struct/1030/4 "2021-02-25T15:57:16Z")
You can follow this issue: [Add capability to alter a struct in query · Issue #6743 · confluentinc/ksql · GitHub](https://github.com/confluentinc/ksql/issues/6743)
---
### Author:  [@harinath-sirigiri](https://forum.confluent.io/u/harinath-sirigiri)
#### Post date: [25 February 2021 16:09 UTC](https://forum.confluent.io/t/ksql-add-new-field-to-existing-struct/1030/5 "2021-02-25T16:09:13Z")
Sure Many Thanks Robin !!
---
### Author:  [@system](https://forum.confluent.io/u/system)
#### Post date: [4 March 2021 16:09 UTC](https://forum.confluent.io/t/ksql-add-new-field-to-existing-struct/1030/6 "2021-03-04T16:09:20Z")
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