Schema Transforms Supported Types

Table mapping Kafka Connect schema data types, such as int32, timestamp, and decimal, to equivalent SQL types in PostgreSQL, MySQL, and Oracle.

Very simple example of a JSON payload:

{
  "id" : 1,
  "customer_id" : 1234,
  "customer_name" : "John Doe"
}

And the corresponding schema:

{
  "type" : "struct",
  "fields" : [ {
    "type" : "int64",
    "optional" : false,
    "field" : "id"
  }, {
    "type" : "int64",
    "optional" : false,
    "field" : "customer_id"
  }, {
    "type" : "string",
    "optional" : false,
    "field" : "customer_name"
  } ],
  "optional" : false
}

To make it easier to use the Kafka types, please find below the list of supported types mapped to usual SQL types that might be found in source database.

Kafka Type	SQL Type (PostgreSQL)	SQL Type (MySQL)	SQL Type (Oracle)
int8	SMALLINT	TINYINT	NUMBER(3)
int16	INTEGER	SMALLINT	NUMBER(5)
int32	INTEGER	INT	NUMBER(10)
int64	BIGINT	BIGINT	NUMBER(19)
float	REAL	FLOAT	NUMBER(7, 2)
double	DOUBLE PRECISION	DOUBLE	NUMBER(15, 6)
string	VARCHAR	VARCHAR	VARCHAR2
bytes	BYTEA	BLOB	BLOB
boolean	BOOLEAN	BOOLEAN	NUMBER(1)
`{"type":"int64","optional":false,"name":"org.apache.kafka.connect.data.Timestamp"}`	TIMESTAMP	TIMESTAMP	TIMESTAMP
`{"type":"bytes","optional":false,"name":"org.apache.kafka.connect.data.Decimal","parameters":{"scale":"4","connect.decimal.precision":"38"}}`	DECIMAL(38,4)	DECIMAL(38,4)	DECIMAL(38,4)
`{"type":"int32","optional":false,"name":"org.apache.kafka.connect.data.Date"}`	DATE	DATE	DATE
`{"type":"int64","optional":false,"name":"org.apache.kafka.connect.data.Time"}`	TIME	TIME	N/A

DECIMAL(38,4) means a decimal number with up to 38 digits in total, of which 4 digits can be after the decimal point, one can adjust the precision if needed.

Please see the example of primitive Kafka Schema definitions and their corresponding payloads:

{"schema":{"type":"boolean","optional":false,"default":false},"payload":false}
{"schema":{"type":"int8","optional":false,"default":1},"payload":1}
{"schema":{"type":"int16","optional":false,"default":1},"payload":1}
{"schema":{"type":"int32","optional":false,"default":1},"payload":1}
{"schema":{"type":"int64","optional":false,"default":1},"payload":1}
{"schema":{"type":"float","optional":false,"default":1.0},"payload":1.0}
{"schema":{"type":"double","optional":false,"default":1.0},"payload":1.0}
{"schema":{"type":"bytes","optional":false,"default":"Zm9v"},"payload":"Zm9v"}
{"schema":{"type":"string","optional":false,"default":"foo"},"payload":"foo"}
{"schema":{"type":"bytes","optional":false,"name":"org.apache.kafka.connect.data.Decimal","parameters":{"scale":"4","connect.decimal.precision":"38"},"default":"EtaH"},"payload":"EtaH"}
{"schema":{"type":"int64","optional":false,"name":"org.apache.kafka.connect.data.Timestamp","default":1758635042028},"payload":1758635042028}
{"schema":{"type":"int64","optional":false,"name":"org.apache.kafka.connect.data.Time","default":55800000},"payload":55800000}
{"schema":{"type":"int32","optional":false,"name":"org.apache.kafka.connect.data.Date","default":20370},"payload":20370}