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sql_raw output

Executes an arbitrary SQL query for each message.

# Common config fields, showing default values
output:
  label: ""
  sql_raw:
    driver: "" # No default (required)
    dsn: "" # No default (required)
    query: "" # No default (optional)
    args_mapping: "" # No default (optional)
    queries: [] # No default (optional)
    max_in_flight: 64
    batching:
      count: 0
      byte_size: 0
      period: ""
      check: ""

When multiple queries are configured, all messages within a batch are executed in a single database transaction. Single-query configurations execute each message individually without a transaction, preserving per-message error granularity. When consuming from Kafka, messages are automatically ordered by partition within the transaction, allowing max_in_flight > 1 to parallelize across partitions while preserving consume order within each partition. Messages without kafka_partition metadata default to partition 0.

Examples​

Table Insert (MySQL)​

Here we insert rows into a database by populating the columns id, name and topic with values extracted from messages and metadata:

output:
  sql_raw:
    driver: mysql
    dsn: foouser:foopassword@tcp(localhost:3306)/foodb
    query: "INSERT INTO footable (id, name, topic) VALUES (?, ?, ?);"
    args_mapping: |
      root = [
        this.user.id,
        this.user.name,
        meta("kafka_topic"),
      ]

Dynamically Creating Tables (PostgreSQL)​

Here we dynamically create output tables transactionally with inserting a record into the newly created table.

output:
  processors:
    - mapping: |
        root = this
        # Prevent SQL injection when using unsafe_dynamic_query
        meta table_name = "\"" + metadata("table_name").replace_all("\"", "\"\"") + "\""
  sql_raw:
    driver: postgres
    dsn: postgres://localhost/postgres
    unsafe_dynamic_query: true
    queries:
      - query: |
          CREATE TABLE IF NOT EXISTS ${!metadata("table_name")} (id varchar primary key, document jsonb);
      - query: |
          INSERT INTO ${!metadata("table_name")} (id, document) VALUES ($1, $2)
          ON CONFLICT (id) DO UPDATE SET document = EXCLUDED.document;
        args_mapping: |
          root = [ this.id, this.document.string() ]

Conditional CDC Queries (PostgreSQL)​

Route messages to different SQL operations based on message metadata. Tombstone messages trigger a DELETE, while all other messages perform an upsert. All operations within a batch execute in a single transaction, ordered by Kafka partition.

output:
  sql_raw:
    driver: postgres
    dsn: postgres://localhost/postgres
    max_in_flight: 8
    batching:
      count: 100
      period: 100ms
    queries:
      - when: 'root = meta("kafka_tombstone_message") == "true"'
        query: 'DELETE FROM users WHERE id = $1'
        args_mapping: 'root = [this.id]'
      - query: |
          INSERT INTO users (id, name, updated_at)
          VALUES ($1, $2, $3)
          ON CONFLICT (id) DO UPDATE SET
            name = EXCLUDED.name,
            updated_at = EXCLUDED.updated_at
        args_mapping: 'root = [this.id, this.name, this.updated_at]'

Fields​

driver​

A database driver to use.

Type: string

Options: mysql, postgres, pgx, clickhouse, mssql, sqlite, oracle, snowflake, trino, gocosmos, spanner, databricks

dsn​

A Data Source Name to identify the target database.

==== Drivers

The following is a list of supported drivers, their placeholder style, and their respective DSN formats:

|=== | Driver | Data Source Name Format

| clickhouse | [clickhouse://[username[:password\](https://github.com/ClickHouse/clickhouse-go#dsn)@\][netloc\][:port\]/dbname[?param1=value1&...&paramN=valueN\]^]

| mysql | [username[:password]@][protocol[(address)]]/dbname[?param1=value1&...&paramN=valueN]

| postgres and pgx | postgres://[user[:password]@][netloc][:port][/dbname][?param1=value1&...]

| mssql | sqlserver://[user[:password]@][netloc][:port][?database=dbname&param1=value1&...]

| sqlite | file:/path/to/filename.db[?param&=value1&...]

| oracle | oracle://[username[:password]@][netloc][:port]/service_name?server=server2&server=server3

| snowflake | username[:password]@account_identifier/dbname/schemaname[?param1=value&...&paramN=valueN]

| trino | [http[s\](https://github.com/trinodb/trino-go-client#dsn-data-source-name)://user[:pass\]@host[:port\][?parameters\]^]

| gocosmos | [AccountEndpoint=<cosmosdb-endpoint>;AccountKey=<cosmosdb-account-key>[;TimeoutMs=<timeout-in-ms>\](https://pkg.go.dev/github.com/microsoft/gocosmos#readme-example-usage)[;Version=<cosmosdb-api-version>\][;DefaultDb/Db=<db-name>\][;AutoId=<true/false>\][;InsecureSkipVerify=<true/false>\]^]

| spanner | projects/[PROJECT]/instances/[INSTANCE]/databases/[DATABASE]

| databricks | token:<access-token>@<server-hostname>:<port>/<http-path> |===

Please note that the postgres and pgx drivers enforce SSL by default, you can override this with the parameter sslmode=disable if required. The pgx driver is an alternative to the standard postgres (pq) driver and comes with extra functionality such as support for array insertion.

The snowflake driver supports multiple DSN formats. Please consult the docs for more details. For key pair authentication, the DSN has the following format: <snowflake_user>@<snowflake_account>/<db_name>/<schema_name>?warehouse=<warehouse>&role=<role>&authenticator=snowflake_jwt&privateKey=<base64_url_encoded_private_key>, where the value for the privateKey parameter can be constructed from an unencrypted RSA private key file rsa_key.p8 using openssl enc -d -base64 -in rsa_key.p8 | basenc --base64url -w0 (you can use gbasenc instead of basenc on OSX if you install coreutils via Homebrew). If you have a password-encrypted private key, you can decrypt it using openssl pkcs8 -in rsa_key_encrypted.p8 -out rsa_key.p8. Also, make sure fields such as the username are URL-encoded.

The gocosmos driver is still experimental, but it has support for hierarchical partition keys as well as cross-partition queries. Please refer to the SQL notes for details.

Type: string

query​

The query to execute. The style of placeholder to use depends on the driver, some drivers require question marks (?) whereas others expect incrementing dollar signs ($1, $2, and so on) or colons (:1, :2 and so on). The style to use is outlined in this table:

DriverPlaceholder Style
clickhouseDollar sign
mysqlQuestion mark
postgresDollar sign
pgxDollar sign
mssqlQuestion mark
sqliteQuestion mark
oracleColon
snowflakeQuestion mark
trinoQuestion mark
gocosmosColon

Type: string

unsafe_dynamic_query​

Whether to enable interpolation functions in the query. Great care should be made to ensure your queries are defended against injection attacks.

Type: bool
Default: false

args_mapping​

An optional Bloblang mapping which should evaluate to an array of values matching in size to the number of placeholder arguments in the field query.

Type: string

queries​

A list of query statements. When a when condition is specified on entries, the first query whose condition evaluates to true (or that has no condition) is executed for each message. When no when conditions are present, all queries execute for each message within a transaction. When specifying multiple statements without conditions, they are all executed within a transaction.

Type: array of object

queries[].query​

The query to execute. The style of placeholder to use depends on the driver, some drivers require question marks (?) whereas others expect incrementing dollar signs ($1, $2, and so on) or colons (:1, :2 and so on). The style to use is outlined in this table:

DriverPlaceholder Style
clickhouseDollar sign
mysqlQuestion mark
postgresDollar sign
pgxDollar sign
mssqlQuestion mark
sqliteQuestion mark
oracleColon
snowflakeQuestion mark
trinoQuestion mark
gocosmosColon

Type: string

queries[].args_mapping​

An optional Bloblang mapping which should evaluate to an array of values matching in size to the number of placeholder arguments in the field query.

Type: string

queries[].when​

An optional Bloblang mapping that, when set, is evaluated for each message to determine whether this query should be executed. The mapping should return a boolean value. The first query in the list whose when condition evaluates to true (or that has no when condition) is the one that executes. This enables conditional query routing based on message content or metadata without requiring unsafe_dynamic_query.

Type: string

max_in_flight​

The maximum number of batches to be sending in parallel at any given time.

Type: int
Default: 64

init_files​

An optional list of file paths containing SQL statements to execute immediately upon the first connection to the target database. This is a useful way to initialise tables before processing data. Glob patterns are supported, including super globs (double star).

Care should be taken to ensure that the statements are idempotent, and therefore would not cause issues when run multiple times after service restarts. If both init_statement and init_files are specified the init_statement is executed after the init_files.

If a statement fails for any reason a warning log will be emitted but the operation of this component will not be stopped.

Type: array of string

init_statement​

An optional SQL statement to execute immediately upon the first connection to the target database. This is a useful way to initialise tables before processing data. Care should be taken to ensure that the statement is idempotent, and therefore would not cause issues when run multiple times after service restarts.

If both init_statement and init_files are specified the init_statement is executed after the init_files.

If the statement fails for any reason a warning log will be emitted but the operation of this component will not be stopped.

Type: string

conn_max_idle_time​

An optional maximum amount of time a connection may be idle. Expired connections may be closed lazily before reuse. If value <= 0, connections are not closed due to a connections idle time.

Type: string

conn_max_life_time​

An optional maximum amount of time a connection may be reused. Expired connections may be closed lazily before reuse. If value <= 0, connections are not closed due to a connections age.

Type: string

conn_max_idle​

An optional maximum number of connections in the idle connection pool. If conn_max_open is greater than 0 but less than the new conn_max_idle, then the new conn_max_idle will be reduced to match the conn_max_open limit. If value <= 0, no idle connections are retained. The default max idle connections is currently 2. This may change in a future release.

Type: int
Default: 2

conn_max_open​

An optional maximum number of open connections to the database. If conn_max_idle is greater than 0 and the new conn_max_open is less than conn_max_idle, then conn_max_idle will be reduced to match the new conn_max_open limit. If value <= 0, then there is no limit on the number of open connections. The default is 0 (unlimited).

Type: int

batching​

Allows you to configure a batching policy.

Type: object

batching.count​

A number of messages at which the batch should be flushed. If 0 disables count based batching.

Type: int
Default: 0

batching.byte_size​

An amount of bytes at which the batch should be flushed. If 0 disables size based batching.

Type: int
Default: 0

batching.period​

A period in which an incomplete batch should be flushed regardless of its size.

Type: string
Default: ""

batching.check​

A Bloblang query that should return a boolean value indicating whether a message should end a batch.

Type: string
Default: ""

batching.processors​

A list of processors to apply to a batch as it is flushed. This allows you to aggregate and archive the batch however you see fit. Please note that all resulting messages are flushed as a single batch, therefore splitting the batch into smaller batches using these processors is a no-op.

Type: array of processor