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Run npx skillmds@latest add tomevault-io/schema-change in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

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Is Schema Change free to use?

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Who published Schema Change?

tomevault-io (@tomevault-io) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Schema Change by tomevault-io — Agent Skill

Name: Schema Change
Author: tomevault-io

Schema Change

Use when changing the db-scheduler database schema (adding/removing/altering columns, indexes, or the scheduled_tasks table). Walks through the lock-step update across every supported DB dialect, the matching JdbcCustomization changes, and the documentation copies. Skip for code-only changes that don't touch table structure.

tomevault-io de394fe 2 files · 3.5 KB Updated Sep 17, 2026

File contents

Schema change checklist

The library supports six DB dialects and ships DDL for each. A schema change that misses one dialect ships a broken release. Treat this as a single atomic change.

1. DDL files (test resources)

Update all six in lock-step. Path: db-scheduler/src/test/resources/

hsql_tables.sql
postgresql_tables.sql
mysql_tables.sql
mariadb_tables.sql
mssql_tables.sql
oracle_tables.sql

Read all six first; column ordering and types differ per dialect (e.g. TIMESTAMP WITH TIME ZONE vs DATETIME2 vs TIMESTAMP(6) WITH TIME ZONE). Don't blindly copy from one dialect to another — preserve each dialect's existing type conventions.

There's also postgresql_custom_tablename.sql under src/test/resources/com/github/kagkarlsson/scheduler/ — check whether your change needs to be reflected there too (it tests configurable table name; usually yes if columns change).

2. JdbcCustomization classes

Path: db-scheduler/src/main/java/com/github/kagkarlsson/scheduler/jdbc/

If your change affects how rows are read/written (new column, type change, nullable→ not-null, etc.), update each relevant class:

DefaultJdbcCustomization.java — base behavior
PostgreSqlJdbcCustomization.java
OracleJdbcCustomization.java
MssqlJdbcCustomization.java
MySQLJdbcCustomization.java
MySQL8JdbcCustomization.java
MariaDBJdbcCustomization.java
AutodetectJdbcCustomization.java — only if dialect-detection logic changes
JdbcCustomization.java (interface) — if the contract itself changes

Also check JdbcTaskRepository.java and QueryBuilder.java for SQL that references the changed columns.

3. Documentation DDL copies

The README and/or docs/ may carry copies of the DDL for users. Grep for a column name from the table to find them:

grep -rn "scheduled_tasks" --include="*.md" .

Update any matching SQL blocks so users get the current schema.

4. Verify

mvn -pl db-scheduler test                                # PostgreSQL tests

Dialects other than PostgreSQL currently need to be tested on CI (need to run on amd64 arch).

5. Migration note for users

Schema changes are user-visible. Add a brief migration note to the changelog / release notes describing the required ALTER TABLE (per dialect if they differ).

6. Finalize

Run /finalize before committing.

Source: kagkarlsson/db-scheduler — distributed by TomeVault.

---name: schema-changedescription: Use when changing the db-scheduler database schema (adding/removing/altering columns, indexes, or the scheduled_tasks table). Walks through the lock-step update across every supported DB dialect, the matching JdbcCustomization changes, and the documentation copies. Skip for code-only changes that don't touch table structure.---# Schema change checklistThe library supports six DB dialects and ships DDL for each. A schema change thatmisses one dialect ships a broken release. Treat this as a single atomic change.## 1. DDL files (test resources)Update **all six** in lock-step. Path: `db-scheduler/src/test/resources/`- `hsql_tables.sql`- `postgresql_tables.sql`- `mysql_tables.sql`- `mariadb_tables.sql`- `mssql_tables.sql`- `oracle_tables.sql`Read all six first; column ordering and types differ per dialect (e.g. `TIMESTAMP WITHTIME ZONE` vs `DATETIME2` vs `TIMESTAMP(6) WITH TIME ZONE`). Don't blindly copy fromone dialect to another — preserve each dialect's existing type conventions.There's also `postgresql_custom_tablename.sql` under`src/test/resources/com/github/kagkarlsson/scheduler/` — check whether your changeneeds to be reflected there too (it tests configurable table name; usually yes ifcolumns change).## 2. JdbcCustomization classesPath: `db-scheduler/src/main/java/com/github/kagkarlsson/scheduler/jdbc/`If your change affects how rows are read/written (new column, type change, nullable→not-null, etc.), update each relevant class:- `DefaultJdbcCustomization.java` — base behavior- `PostgreSqlJdbcCustomization.java`- `OracleJdbcCustomization.java`- `MssqlJdbcCustomization.java`- `MySQLJdbcCustomization.java`- `MySQL8JdbcCustomization.java`- `MariaDBJdbcCustomization.java`- `AutodetectJdbcCustomization.java` — only if dialect-detection logic changes- `JdbcCustomization.java` (interface) — if the contract itself changesAlso check `JdbcTaskRepository.java` and `QueryBuilder.java` for SQL that referencesthe changed columns.## 3. Documentation DDL copiesThe README and/or `docs/` may carry copies of the DDL for users. Grep for a columnname from the table to find them:```bashgrep -rn "scheduled_tasks" --include="*.md" .```Update any matching SQL blocks so users get the current schema.## 4. Verify```bashmvn -pl db-scheduler test # PostgreSQL tests```Dialects other than PostgreSQL currently need to be tested on CI (need to run on amd64 arch).## 5. Migration note for usersSchema changes are user-visible. Add a brief migration note to the changelog / releasenotes describing the required `ALTER TABLE` (per dialect if they differ).## 6. FinalizeRun `/finalize` before committing.---> Source: [kagkarlsson/db-scheduler](https://github.com/kagkarlsson/db-scheduler) — distributed by [TomeVault](https://tomevault.io).

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