Cloud

sql_select

Executes a select query and creates a message for each row received.

Once the rows from the query are exhausted this input shuts down, allowing the pipeline to gracefully terminate (or the next input in a sequence to execute).

  • Common

  • Advanced

input:
  label: ""
  sql_select:
    driver: "" # No default (required)
    dsn: "" # No default (required)
    table: "" # No default (required)
    columns: [] # No default (required)
    where: "" # No default (optional)
    args_mapping: "" # No default (optional)
    auto_replay_nacks: true
input:
  label: ""
  sql_select:
    driver: "" # No default (required)
    dsn: "" # No default (required)
    table: "" # No default (required)
    columns: [] # No default (required)
    where: "" # No default (optional)
    args_mapping: "" # No default (optional)
    prefix: "" # No default (optional)
    suffix: "" # No default (optional)
    auto_replay_nacks: true
    init_files: [] # No default (optional)
    init_statement: "" # No default (optional)
    conn_max_idle_time: "" # No default (optional)
    conn_max_life_time: "" # No default (optional)
    conn_max_idle: 2
    conn_max_open: 0 # No default (optional)

Examples

Consume a Table (PostgreSQL)

Here we define a pipeline that will consume all rows from a table created within the last hour by comparing the unix timestamp stored in the row column "created_at":

input:
  sql_select:
    driver: postgres
    dsn: postgres://foouser:foopass@localhost:5432/testdb?sslmode=disable
    table: footable
    columns: [ '*' ]
    where: created_at >= ?
    args_mapping: |
      root = [
        now().ts_unix() - 3600
      ]

Fields

args_mapping

An optional Bloblang mapping that evaluates to an array of values, one for each placeholder in the where field, in order. The values are passed to the driver as query arguments.

Type: string

# Examples:
args_mapping: root = [ "article", now().ts_format("2006-01-02") ]

auto_replay_nacks

Whether to automatically replay rejected messages (negative acknowledgements, or nacks) at the output level. If the cause of rejections persists, leaving this option enabled can result in back pressure.

Set auto_replay_nacks to false to delete rejected messages. Disabling auto replays can greatly improve memory efficiency of high throughput streams, as the original shape of the data is discarded immediately upon consumption and mutation.

Type: bool

Default: true

columns[]

A list of columns to select.

Type: array<string>

# Examples:
columns:
  - "*"

# ---

columns:
  - foo
  - bar
  - baz

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_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_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

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 table lists the supported drivers and their DSN formats:

Driver Data Source Name Format

clickhouse

clickhouse://[username[:password]@][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]://user[:pass]@host[:port][?parameters]

gocosmos

AccountEndpoint=<cosmosdb-endpoint>;AccountKey=<cosmosdb-account-key>[;TimeoutMs=<timeout-in-ms>][;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

# Examples:
dsn: clickhouse://username:password@host1:9000,host2:9000/database?dial_timeout=200ms&max_execution_time=60

# ---

dsn: foouser:foopassword@tcp(localhost:3306)/foodb

# ---

dsn: postgres://foouser:foopass@localhost:5432/foodb?sslmode=disable

# ---

dsn: oracle://foouser:foopass@localhost:1521/service_name

# ---

dsn: token:dapi1234567890ab@dbc-a1b2345c-d6e7.cloud.databricks.com:443/sql/1.0/warehouses/abc123def456

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<string>

# Examples:
init_files:
  - ./init/*.sql

# ---

init_files:
  - ./foo.sql
  - ./bar.sql

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

# Examples:
init_statement: |

  CREATE TABLE IF NOT EXISTS some_table (
    foo varchar(50) not null,
    bar integer,
    baz varchar(50),
    primary key (foo)
  ) WITHOUT ROWID;

prefix

Optional SQL text to add before the SELECT keyword, such as a WITH clause.

Type: string

suffix

Optional SQL text to append after the generated SELECT statement, such as an ORDER BY, LIMIT, or locking clause.

Type: string

table

The table to select from.

Type: string

# Examples:
table: foo

where

An optional where clause to add. Placeholder arguments are populated with the args_mapping field. Always use question marks for placeholders. They are converted to dollar syntax ($1) when the postgres, pgx, or clickhouse driver is used, and to colon syntax (:1) when the oracle or gocosmos driver is used.

Type: string

# Examples:
where: type = ? and created_at > ?

# ---

where: user_id = ?