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))