Function diffSchema

diffSchema(
schema: ObjectSchemaBuilder<any, any, any, any, any, any, any>,
dbState: DatabaseTableState,
): MigrationDiff
Compare a code-first schema model against a live database table state and produce a diff describing the changes needed to bring the database in sync.
Parameters
- schema: ObjectSchemaBuilder<any, any, any, any, any, any, any>
  The code-first ObjectSchemaBuilder.
- dbState: DatabaseTableState
  The current database state from introspectDatabase.
Returns MigrationDiff
A MigrationDiff describing columns, indexes, and foreign keys to add, drop, or alter.
Example
```
const dbState = await introspectDatabase(knex, 'users');
const diff = diffSchema(UserSchema, dbState);
if (diff.addColumns.length > 0) {
    const migration = generateMigration(diff, 'users');
    console.log(migration.up);
}
```
- Defined in knex-schema/src/migration.ts:337