MySQL syntax

Set "engine": "mysql" to write a version source for MySQL or MariaDB. Everything in shared syntax applies; this page covers what is specific to MySQL.

{
  "engine": "mysql",
  "name": "example-db",
  "version": [
    {
      "_id": "1.0.0",
      "createtable": {
        "users": {
          "primary_key": "id",
          "id": { "type": "INT", "auto_increment": true },
          "email": { "type": "VARCHAR", "length": 255, "unique": true },
          "settings": { "type": "JSON", "null": true },
          "created_at": { "type": "DATETIME", "default": "CURRENT_TIMESTAMP" }
        }
      }
    }
  ]
}

Column types

Types are written in uppercase.

Length

length sets the size of a column, such as "length": 255 for a VARCHAR. DECIMAL and FLOAT accept a decimal length; other types need a whole number.

Auto increment

To create an auto-incrementing column, add "auto_increment": true.

"id": { "type": "INT", "auto_increment": true }

The verifier flags these combinations as critical errors:

• auto_increment together with "null": true.
• auto_increment on VARCHAR, TEXT, LONGTEXT, DATETIME, DECIMAL or JSON columns.
• unique on a JSON column.

MySQL-only behaviour

• Recreating a column: modifycolumn keeps the properties you don’t specify, unless you set recreate to rebuild the column.
• Dropping a primary key also removes AUTO_INCREMENT from the column.
• Partial indexes (an index condition) are not supported.