yamltodb - YAML to Database

Name

yamltodb -- generate SQL statements to update a PostgreSQL database to match the schema specified in a YAML file

Synopsys

yamltodb [option...] dbname [spec]

Description

yamltodb is a utility for generating SQL statements to update a PostgreSQL database so that it will match the schema specified in an input YAML formatted specification file.

For example, given the input file shown under dbtoyaml, yamltodb outputs the following SQL statements:

CREATE SCHEMA s1;
CREATE TABLE t1 (
    c1 integer NOT NULL,
    c2 smallint,
    c3 boolean DEFAULT false,
    c4 text);
CREATE TABLE s1.t2 (
    c21 integer NOT NULL,
    c22 character varying(16));
ALTER TABLE s1.t2 ADD CONSTRAINT t2_pkey PRIMARY KEY (c21);
ALTER TABLE t1 ADD CONSTRAINT t1_pkey PRIMARY KEY (c1);
ALTER TABLE t1 ADD CONSTRAINT t1_c2_fkey FOREIGN KEY (c2) REFERENCES s1.t2 (c21);

Options

yamltodb accepts the following command-line arguments (in addition to the cmdargs):

dbname

Specifies the name of the database whose schema is to analyzed.

spec

Specifies the location of the YAML specification. If this is omitted or specified as a single or double dash, the specification is read from the program's standard input.

-n schema, --schema= schema

Compare only a schema matching schema. By default, all schemas are compared. Multiple schemas can be compared by using multiple -n switches.

-1, --single-transaction

Wrap the generated statements in BEGIN/COMMIT. This ensures that either all the statements complete successfully, or no changes are applied.

-u, --update

Execute the generated statements against the database mentioned in dbname. This implies the --single-transaction option.

Examples

Given a YAML file named moviesdb.yaml, to generate SQL statements to update a database called mymovies:

yamltodb mymovies moviesdb.yaml

To generate the statements as above and immediately update mymovies:

yamltodb mymovies moviesdb.yaml | psql mymovies

or:

yamltodb --update mymovies moviesdb.yaml

To generate the statements directly from the ouput of dbtoyaml (against a different database), with statements enclosed in a single transaction, and save the statements in a file named mymovies.sql:

dbtoyaml devmovies | yamltodb -1 mymovies -o mymovies.sql