machbase-neo
Bridges
Bridge - PostgreSQL

Bridge - PostgreSQL

Register a bridge to postgresql

Register a bridge that connects to the postgreSQL database.

bridge add -t postgres pg host=127.0.0.1 port=5432 user=dbuser dbname=postgres sslmode=disable;

Connect options

OptionDescriptionexample
dbnameThe name of the database to connect to
userThe user to sign in as
passwordThe user’s password
hostThe host to connect to. Values that start with / are for unix domain sockets. default is localhosthost=127.0.0.1
portThe port to bind to. default is 5432
sslmodeWhether or not to use SSL (default is require)(see below)
connect_timeoutMaximum wait for connection, in seconds. Zero or not specified means wait indefinitely.
sslcertCert file location. The file must contain PEM encoded data.
sslkeyKey file location. The file must contain PEM encoded data.
sslrootcertThe location of the root certificate file. The file must contain PEM encoded data.

Valid values for sslmode are:

sslmodeDescription
disableNo SSL
requireAlways SSL (skip verification)
verify-caAlways SSL (verify that the certificate presented by the server was signed by a trusted CA)
verify-fullAlways SSL (verify that the certification presented by the server was signed by a trusted CA and the server host name matches the one in the certificate)

Create table

Open machbase-neo shell and execute the command below which creates a pg_example table via the pg bridge.

bridge exec pg CREATE TABLE IF NOT EXISTS pg_example(
    id         SERIAL PRIMARY KEY,
    company    VARCHAR(50) UNIQUE NOT NULL,
    employee   INT,
    discount   REAL,
    plan       FLOAT(8),
    code       UUID,
    valid      BOOL,
    memo       TEXT,
    created_on TIMESTAMP NOT NULL
);

Can make sure the table has been created with psql command line tool

postgres=# \d pg_example;
                                        Table "public.pg_example"
   Column   |            Type             | Collation | Nullable |                Default                 
------------+-----------------------------+-----------+----------+----------------------------------------
 id         | integer                     |           | not null | nextval('pg_example_id_seq'::regclass)
 company    | character varying(50)       |           | not null | 
 employee   | integer                     |           |          | 
 discount   | real                        |           |          | 
 plan       | real                        |           |          | 
 code       | uuid                        |           |          | 
 valid      | boolean                     |           |          | 
 memo       | text                        |           |          | 
 created_on | timestamp without time zone |           | not null | 
Indexes:
    "pg_example_pkey" PRIMARY KEY, btree (id)
    "pg_example_company_key" UNIQUE CONSTRAINT, btree (company)

TQL writing on the PostgreSQL 

BYTES(payload() ?? `{
  "company": "acme",
  "employee": 10
}`)
SCRIPT("tengo", {
  // get current time
  times := import("times")
  ts := times.now()
  // get tql context
  ctx := import("context")
  val := ctx.value()
  // parse json
  json := import("json")
  msg := json.decode(val[0])
  ctx.yield(msg.company, msg.employee, ts)
})
INSERT(bridge("pg"), table("pg_example"), "company", "employee", "created_on")
postgres=# select * from pg_example;
 id | company | employee | discount | plan | code | valid | memo |         created_on         
----+---------+----------+----------+------+------+-------+------+----------------------------
  1 | acme    |       10 |          |      |      |       |      | 2023-08-09 11:05:30.039961
(1 row)

TQL reading from the PostgreSQL 

SQL(bridge('pg'), "select * from pg_example")
CSV()
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