yamltodb - YAML to Database

Name

yamltodb – generate SQL statements to update a Postgres 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 Postgres 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 - Database to YAML, yamltodb, when run against a newly-created database, outputs the following SQL statements:

CREATE SCHEMA s1;
ALTER SCHEMA s1 OWNER TO bob;
GRANT ALL ON SCHEMA s1 TO bob;
GRANT ALL ON SCHEMA s1 TO alice;
CREATE TABLE t1 (
    c1 integer NOT NULL,
    c2 smallint,
    c3 boolean DEFAULT false,
    c4 text);
ALTER TABLE t1 OWNER TO alice;
CREATE TABLE s1.t2 (
    c21 integer NOT NULL,
    c22 character varying(16));
ALTER TABLE s1.t2 OWNER TO bob;
GRANT ALL ON TABLE s1.t2 TO bob;
GRANT SELECT ON TABLE s1.t2 TO PUBLIC;
GRANT INSERT, DELETE, UPDATE ON TABLE s1.t2 TO alice WITH GRANT OPTION;
GRANT INSERT ON TABLE s1.t2 TO carol;
ALTER TABLE t1 ADD CONSTRAINT t1_c2_check CHECK (c2 > 123);
ALTER TABLE t1 ADD CONSTRAINT t1_pkey PRIMARY KEY (c1);
ALTER TABLE s1.t2 ADD CONSTRAINT t2_pkey PRIMARY KEY (c21);
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 Common Command Line Options):

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. However, if the --multiple-files option is used, that takes precedence.
-m, --multiple-files

Specifies that input should be taken from YAML specification files present in a two-level (metadata) directory tree. See Multiple File Output under dbtoyaml - Database to YAML for further details.

-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.

--revert

Generate SQL in reversion mode, that is, to undo the changes that would normally be generated. For example, if without this option, the SQL would be a DROP TABLE, the --revert option generates a CREATE TABLE with all the columns, constraints and other objects associated with the table being dropped.

This option is experimental and currently has only been implemented for schemas and sequences.

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