增加创建表时支持注释，创建字段和修改字段时支持注释

dialects/dialect.go

@@ -206,7 +206,7 @@ func (db *Base) IsColumnExist(queryer core.Queryer, ctx context.Context, tableNa
 // AddColumnSQL returns a SQL to add a column
 func (db *Base) AddColumnSQL(tableName string, col *schemas.Column) string {
 	s, _ := ColumnString(db.dialect, col, true)
-	return fmt.Sprintf("ALTER TABLE %v ADD %v", db.dialect.Quoter().Quote(tableName), s)
+	return fmt.Sprintf("ALTER TABLE %s ADD %s", db.dialect.Quoter().Quote(tableName), s)
 }
 
 // CreateIndexSQL returns a SQL to create index

dialects/mysql.go

@@ -685,6 +685,12 @@ func (db *mysql) CreateTableSQL(ctx context.Context, queryer core.Queryer, table
 		b.WriteString(db.rowFormat)
 	}
 
+	if table.Comment != ""  {
+		b.WriteString(" COMMENT='")
+		b.WriteString(table.Comment)
+		b.WriteString("'")
+	}
+
 	return b.String(), true, nil
 }
 

dialects/postgres.go

@@ -991,13 +991,37 @@ func (db *postgres) IsTableExist(queryer core.Queryer, ctx context.Context, tabl
 		db.getSchema(), tableName)
 }
 
-func (db *postgres) ModifyColumnSQL(tableName string, col *schemas.Column) string {
+func (db *postgres) AddColumnSQL(tableName string, col *schemas.Column) string {
+	s, _ := ColumnString(db.dialect, col, true)
+
+	quoter := db.dialect.Quoter()
+	addColumnSQL := ""
+	commentSQL := "; "
 	if len(db.getSchema()) == 0 || strings.Contains(tableName, ".") {
-		return fmt.Sprintf("alter table %s ALTER COLUMN %s TYPE %s",
+		addColumnSQL = fmt.Sprintf("ALTER TABLE %s ADD %s", quoter.Quote(tableName), s)
-			db.quoter.Quote(tableName), db.quoter.Quote(col.Name), db.SQLType(col))
+		commentSQL += fmt.Sprintf("COMMENT ON COLUMN %s.%s IS '%s'", quoter.Quote(tableName), quoter.Quote(col.Name), col.Comment)
+		return addColumnSQL + commentSQL
 	}
-	return fmt.Sprintf("alter table %s.%s ALTER COLUMN %s TYPE %s",
+
-		db.quoter.Quote(db.getSchema()), db.quoter.Quote(tableName), db.quoter.Quote(col.Name), db.SQLType(col))
+	addColumnSQL = fmt.Sprintf("ALTER TABLE %s.%s ADD %s", quoter.Quote(tableName), s)
+	commentSQL += fmt.Sprintf("COMMENT ON COLUMN %s.%s IS '%s'", quoter.Quote(db.getSchema()), quoter.Quote(tableName), quoter.Quote(col.Name), col.Comment)
+	return addColumnSQL + commentSQL
+}
+
+func (db *postgres) ModifyColumnSQL(tableName string, col *schemas.Column) string {
+	quoter := db.dialect.Quoter()
+	modifyColumnSQL := ""
+	commentSQL := "; "
+
+	if len(db.getSchema()) == 0 || strings.Contains(tableName, ".") {
+		modifyColumnSQL = fmt.Sprintf("ALTER TABLE %s ALTER COLUMN %s TYPE %s", quoter.Quote(tableName), quoter.Quote(col.Name), db.SQLType(col))
+		commentSQL += fmt.Sprintf("COMMENT ON COLUMN %s.%s IS '%s'", quoter.Quote(tableName), quoter.Quote(col.Name), col.Comment)
+		return modifyColumnSQL + commentSQL
+	}
+
+	modifyColumnSQL = fmt.Sprintf("ALTER TABLE %s.%s ALTER COLUMN %s TYPE %s", quoter.Quote(db.getSchema()), quoter.Quote(tableName), quoter.Quote(col.Name), db.SQLType(col))
+	commentSQL += fmt.Sprintf("COMMENT ON COLUMN %s.%s.%s IS '%s'", quoter.Quote(db.getSchema()), quoter.Quote(tableName), quoter.Quote(col.Name), col.Comment)
+	return modifyColumnSQL + commentSQL
 }
 
 func (db *postgres) DropIndexSQL(tableName string, index *schemas.Index) string {
@@ -1302,6 +1326,26 @@ func (db *postgres) GetIndexes(queryer core.Queryer, ctx context.Context, tableN
 	return indexes, nil
 }
 
+func (db *postgres) CreateTableSQL(ctx context.Context, queryer core.Queryer, table *schemas.Table, tableName string) (string, bool, error) {
+	quoter := db.dialect.Quoter()
+	if len(db.getSchema()) != 0 && !strings.Contains(tableName, ".") {
+		tableName = fmt.Sprintf("%s.%s", db.getSchema(), tableName)
+	}
+
+	createTableSQL, ok, err := db.Base.CreateTableSQL(ctx, queryer, table, tableName)
+	if err != nil {
+		return "", ok, err
+	}
+
+	commentSql := "; "
+	if table.Comment != "" {
+		// support schema.table -> "schema"."table"
+		commentSql += fmt.Sprintf("COMMENT ON TABLE %s IS '%s'", quoter.Quote(tableName), table.Comment)
+	}
+
+	return createTableSQL + commentSql, true, nil
+}
+
 func (db *postgres) Filters() []Filter {
 	return []Filter{&SeqFilter{Prefix: "$", Start: 1}}
 }

session_schema.go

@@ -352,29 +352,9 @@ func (session *Session) Sync(beans ...interface{}) error {
 					return err
 				}
 
-				// add column comment for postgres
-				if col.Comment != "" && engine.Dialect().URI().DBType == schemas.POSTGRES {
-					// @see: integrations/engine_test.go#TestGetColumns
-					addColumnCommentSql := fmt.Sprintf("COMMENT ON COLUMN %s.%s IS '%s'", session.engine.Quote(tbNameWithSchema), session.engine.Quote(col.Name), col.Comment)
-					_, err = session.Exec(addColumnCommentSql)
-					if err != nil {
-						return err
-					}
-				}
-
 				continue
 			}
 
-			// add column comment for postgres
-			if col.Comment != "" && engine.Dialect().URI().DBType == schemas.POSTGRES {
-				// @see: integrations/engine_test.go#TestGetColumns
-				addColumnCommentSql := fmt.Sprintf("COMMENT ON COLUMN %s.%s IS '%s'", session.engine.Quote(tbNameWithSchema), session.engine.Quote(col.Name), col.Comment)
-				_, err = session.Exec(addColumnCommentSql)
-				if err != nil {
-					return err
-				}
-			}
-
 			err = nil
 			expectedType := engine.dialect.SQLType(col)
 			curType := engine.dialect.SQLType(oriCol)
@@ -415,6 +395,8 @@ func (session *Session) Sync(beans ...interface{}) error {
 						_, err = session.exec(engine.dialect.ModifyColumnSQL(tbNameWithSchema, col))
 					}
 				}
+			} else if col.Comment != oriCol.Comment {
+				_, err = session.exec(engine.dialect.ModifyColumnSQL(tbNameWithSchema, col))
 			}
 
 			if col.Default != oriCol.Default {

tags/parser.go

@@ -90,6 +90,14 @@ func (parser *Parser) ParseWithCache(v reflect.Value) (*schemas.Table, error) {
 		return nil, err
 	}
 
+	// if bean has Comment Method, then set table.Comment
+	if _, ok := t.MethodByName("Comment"); ok {
+		tableCommentFn := v.MethodByName("Comment")
+		if tableCommentFn.Type().String() == "func() string" {
+			table.Comment = fmt.Sprintf("%s", tableCommentFn.Call(nil)[0])
+		}
+	}
+
 	parser.tableCache.Store(t, table)
 
 	if parser.cacherMgr.GetDefaultCacher() != nil {