Database schema operation

3. database meta information

xorm provides methods to getting and setting table schema. For less schema changing production, engine.Sync2() is enough.

3.1 retrieve database meta info

  • DBMetas()

engine.DBMetas() returns all tables schema information.

3.2.directly table operation

  • CreateTables()

engine.CreateTables(struct) creates table with struct or struct pointer. engine.Charset() and engine.StoreEngine() can change charset or storage engine for mysql database.

  • IsTableEmpty()

check table is empty or not.

  • IsTableExist()

check table is existed or not.

  • DropTables()

engine.DropTables(struct) drops table and indexes with struct or struct pointer. engine.DropTables(string) only drops table except indexes.

3.3.create indexes and uniques

  • CreateIndexes create indexes with struct.

  • CreateUniques create unique indexes with struct.

3.4.Synchronize database schema

xorm watches tables and indexes and sync schema:

  1. use table name to create or drop table
  2. use column name to alter column
  3. use the indexes definition in struct field tag to create or drop indexes.
err := engine.Sync2(new(User))