MySQL Schema Diff

Normalize and compare two MySQL CREATE TABLE dumps from the command line.

The script removes dump comments, blank lines, table constraints, and selected storage-engine details before sending the normalized files to diff, icdiff, or Meld. It does not connect to MySQL or modify the input files.

Requirements

• Bash
• awk, sed, and diff
• optional: icdiff or Meld for the corresponding output mode

The script works in a regular Linux or macOS Bash environment and in Git Bash on Windows.

Usage

git clone https://github.com/alsd4git/mysql-schema-diff.git
cd mysql-schema-diff
./SqlCompare.sh old-schema.sql new-schema.sql MODE

MODE selects the comparison program. Run ./SqlCompare.sh -h for the current command syntax.

Mode	Output
1	colored terminal output through icdiff
2	Windows Meld installed under Program Files (x86)
3	standard diff with color
4	side-by-side diff filtered through colored grep

Example

mysqldump --no-data app_before > before.sql
mysqldump --no-data app_after > after.sql
./SqlCompare.sh before.sql after.sql 1

The command writes clean_before.sql and clean_after.sql beside the inputs. Review and remove those generated files after the comparison. Normalization does not prove that a migration is safe or reversible.

Development

shellcheck SqlCompare.sh tests/test-sql-compare.sh
./tests/test-sql-compare.sh

GitHub Actions runs the smoke tests on Linux and macOS.

License

MIT. See LICENSE.