Tweaks #996

Author: tyt2y3

src/backend/mysql/table.rs

@@ -190,11 +190,8 @@ impl TableBuilder for MysqlQueryBuilder {
                         sql.write_str(" TO ").unwrap();
                         self.prepare_iden(to_name, sql);
                     }
-                    TableAlterOption::DropColumn(DropColumnOption { column_name, if_exists }) => {
+                    TableAlterOption::DropColumn(DropColumnOption { column_name, .. }) => {
                         sql.write_str("DROP COLUMN ").unwrap();
-                        if *if_exists{
-                             panic!("MySQL does not support drop column if exists");
-                        }
                         self.prepare_iden(column_name, sql);
                     }
                     TableAlterOption::DropForeignKey(name) => {

src/backend/sqlite/table.rs

@@ -62,14 +62,8 @@ impl TableBuilder for SqliteQueryBuilder {
                 sql.write_str(" TO ").unwrap();
                 self.prepare_iden(to_name, sql);
             }
-            TableAlterOption::DropColumn(DropColumnOption {
-                column_name,
-                if_exists,
-            }) => {
+            TableAlterOption::DropColumn(DropColumnOption { column_name, .. }) => {
                 sql.write_str("DROP COLUMN ").unwrap();
-                if *if_exists {
-                    panic!("Sqlite does not support drop column if exists");
-                }
                 self.prepare_iden(column_name, sql);
             }
             TableAlterOption::DropForeignKey(_) => {