Breaking changes

• Type dbdiff diff <source> <target>. The bare form without diff is removed.
• The --driver flag is now optional. dbdiff detects the engine from the source and the target.
• The old drivers package moves to internal. The new drivers and migrations packages give the stable Go API.

Highlights

• Go API: drivers.Diff returns the statements of a diff, and migrations.Up and migrations.Status run the migrations, with functional options.
• Migrations: the migrate command group builds migration files from a diff and applies them with a lock and a history table. Seven subcommands: generate, status, preview, up, step, verify, and repair.
• SQL sources: an argument can name a .sql file or a directory of .sql files.
• Data comparison: the --data flag compares the rows of each table that holds a primary key.
• New diff flags: --comments, --privileges, --exit-code, and --version.
• PostgreSQL: the diff compares partitions, materialized views, policies, rules, procedures, extended statistics, identity and generated columns, object comments, and more.
• SQLite: the diff compares virtual tables, constraint names and clauses, index key options, and the parts of a CREATE TABLE statement that no PRAGMA reports.
• A .sql file with -- dbdiff:no-transaction, or the Atlas line -- atlas:txmode none, runs one call for each statement.

Fixes

• SQLite: the driver quotes every identifier, recreates a table safely, and guesses a rename with one candidate only.
• PostgreSQL: the statement order is stable, a column can change between serial and a plain integer, and a recreated object keeps its owner, grants, policies, and triggers.
• Data comparison: timestamps format in UTC, NaN values quote correctly, generated columns skip, and child rows delete before parent rows.
• Migrations: two files of one version give an error, a half-applied file writes a dirty history row, and a .down.sql file does not apply.

Full changelog: v1.1.0...v1.2.0