Add Schema::create_index_from_entity (SeaQL/sea-orm#593)

SeaORM/docs/01-index.md

@@ -40,6 +40,8 @@ If you prefer step-by-step tutorials on how to use SeaORM. You can checkout [Sea
 
 	3.2 [Create Enum](04-generate-database-schema/02-create-enum.md)
 
+	3.3 [Create Index](04-generate-database-schema/03-create-index.md)
+
 4. Migration
 
 	4.1 [Setting Up Migration](05-migration/01-setting-up-migration.md)

SeaORM/docs/04-generate-database-schema/01-create-table.md

@@ -4,6 +4,8 @@ To create tables in database instead of writing [`TableCreateStatement`](https:/
 
 Below we use [`CakeFillingPrice`](https://github.com/SeaQL/sea-orm/blob/master/src/tests_cfg/cake_filling_price.rs) entity to demo its generated SQL statement. You can construct the same statement with [`TableCreateStatement`](https://docs.rs/sea-query/*/sea_query/table/struct.TableCreateStatement.html).
 
+Note that since version `0.7.0`, [`Schema::create_table_from_entity`](https://docs.rs/sea-orm/0.5/sea_orm/schema/struct.Schema.html#method.create_table_from_entity) no longer create indexes. If you need to create indexes in database please check [here](04-generate-database-schema/03-create-index.md) for details.
+
 ```rust
 use sea_orm::{sea_query::*, tests_cfg::*, EntityName, Schema};
 

SeaORM/docs/04-generate-database-schema/03-create-index.md

@@ -0,0 +1,29 @@
+# Create Index
+
+To create indexes in database instead of writing [`IndexCreateStatement`](https://docs.rs/sea-query/*/sea_query/index/struct.IndexCreateStatement.html) manually, you can derive it from `Entity` using [`Schema::create_index_from_entity`](https://docs.rs/sea-orm/0.5/sea_orm/schema/struct.Schema.html#method.create_index_from_entity). This method will help you create database indexes defined in `Entity`.
+
+Below we use [`Indexes`](https://github.com/SeaQL/sea-orm/blob/master/src/tests_cfg/indexes.rs) entity to demo its generated SQL statement. You can construct the same statement with [`IndexCreateStatement`](https://docs.rs/sea-query/*/sea_query/index/struct.IndexCreateStatement.html).
+
+```rust
+use sea_orm::{sea_query, tests_cfg::*, Schema};
+
+let builder = db.get_database_backend();
+let schema = Schema::new(builder);
+
+let stmts = schema.create_index_from_entity(indexes::Entity);
+assert_eq!(stmts.len(), 2);
+
+let idx = sea_query::Index::create()
+    .name("idx-indexes-index1_attr")
+    .table(indexes::Entity)
+    .col(indexes::Column::Index1Attr)
+    .to_owned();
+assert_eq!(builder.build(&stmts[0]), builder.build(&idx));
+
+let idx = sea_query::Index::create()
+    .name("idx-indexes-index2_attr")
+    .table(indexes::Entity)
+    .col(indexes::Column::Index2Attr)
+    .to_owned();
+assert_eq!(builder.build(&stmts[1]), builder.build(&idx));
+```