refactor: alter table first with optional column in mysql

Author: taozhi8833998

pegjs/mysql.pegjs

@@ -1228,12 +1228,12 @@ alter_table_stmt
       };
     }
 alter_column_suffix
-  = k:('after'i / 'first'i) __ i:column_ref {
-    return {
-      keyword: k,
-      expr: i
+  = k:"first"i {
+      return { keyword: k };
+    }
+  / k:"after"i __ i:column_ref {
+      return { keyword: k, expr: i };
     }
-  }
 alter_action_list
   = head:alter_action tail:(__ COMMA __ alter_action)* {
       return createList(head, tail);

pegjs/sqlite.pegjs

@@ -781,12 +781,12 @@ alter_table_stmt
     }
 
 alter_column_suffix
-  = k:('after'i / 'first'i) __ i:column_ref {
-    return {
-      keyword: k,
-      expr: i
+  = k:"first"i {
+      return { keyword: k };
+    }
+  / k:"after"i __ i:column_ref {
+      return { keyword: k, expr: i };
     }
-  }
 
 alter_action_list
   = head:alter_action tail:(__ COMMA __ alter_action)* {

src/alter.js

@@ -64,8 +64,10 @@ function alterExprToSQL(expr) {
     toUpper(prefix),
     name && name.trim(),
     dataType.filter(hasVal).join(' '),
-    suffix && `${toUpper(suffix.keyword)}${suffix.expr ? ` ${columnRefToSQL(suffix.expr)}` : ''}`,
   ]
+  if (suffix) {
+    alterArray.push(toUpper(suffix.keyword), suffix.expr && columnRefToSQL(suffix.expr))
+  }
   return alterArray.filter(hasVal).join(' ')
 }