pg-diff-sync
Takes two objects that describe the structure of a database and produces the PostgreSQL statements required to get from one to the other.
Install
$ npm install pg-diff-sync --save
Usage
const pgDiffSync = require('pg-diff-sync')
const currentDbStructure = {...}
const expectedDbStructure = {...}
const statements = pgDiffSync(
currentDbStructure,
expectedDbStructure
)
// Returns an array of DDL statements to apply on the PostgreSQL database
API
pgDiffSync(baseDbStructure, targetDbStructure)
Arguments:
Arg | Type | Notes |
---|---|---|
baseDbStructure |
object |
An object representing the original starting position of a database - most likely the output conjured from the pg-info package |
targetDbStructure |
object |
And an object representing how the database needs to be - in the same form as baseDbStructure (again see the pg-info package for more details) |
Output
The output from pg-diff-sync is a simple array of strings.
- Each string is a separate DDL statement, that should be run on the PostgreSQL database that produced the
baseDbStructure
object. - With some caveats, running these statements on the base database will turn it into the target database
Example output
[
"CREATE SCHEMA pg_diff_sync_test;",
"COMMENT ON SCHEMA pg_diff_sync_test IS 'Schema auto-generated by Relationize.js!';",
"CREATE TABLE pg_diff_sync_test.people();",
"COMMENT ON TABLE pg_diff_sync_test.people IS 'Just a simple list of people!';",
"ALTER TABLE pg_diff_sync_test.people ADD COLUMN employee_no text NOT NULL;",
"ALTER TABLE pg_diff_sync_test.people ADD COLUMN first_name text NOT NULL;",
"ALTER TABLE pg_diff_sync_test.people ADD COLUMN last_name text NOT NULL;",
"ALTER TABLE pg_diff_sync_test.people ADD COLUMN age integer;",
"ALTER TABLE pg_diff_sync_test.people ADD COLUMN _created timestamp with time zone NOT NULL DEFAULT now();",
"ALTER TABLE pg_diff_sync_test.people ADD COLUMN _created_by text;",
"ALTER TABLE pg_diff_sync_test.people ADD COLUMN _modified timestamp with time zone NOT NULL DEFAULT now();",
"ALTER TABLE pg_diff_sync_test.people ADD COLUMN _modified_by text;",
"COMMENT ON COLUMN pg_diff_sync_test.people.first_name IS 'Person''s first name';",
"COMMENT ON COLUMN pg_diff_sync_test.people.age IS 'Age in years';",
"COMMENT ON COLUMN pg_diff_sync_test.people._created IS 'Timestamp for when this record was created';",
"COMMENT ON COLUMN pg_diff_sync_test.people._created_by IS 'UserID that created this record (if known)';",
"COMMENT ON COLUMN pg_diff_sync_test.people._modified IS 'Timestamp for when this record was last updated';",
"COMMENT ON COLUMN pg_diff_sync_test.people._modified_by IS 'UserID that last modified this record (if known)';",
"ALTER TABLE pg_diff_sync_test.people ADD PRIMARY KEY (employee_no);",
"CREATE UNIQUE INDEX people_first_name_last_name_idx ON pg_diff_sync_test.people (first_name,last_name);"
]
Testing
$ npm test