Fix

Author: Huliiiiii

src/backend/table_builder.rs

@@ -112,8 +112,19 @@ pub trait TableBuilder:
         }
 
         if let Some(default) = default {
-            write!(sql, " DEFAULT ").unwrap();
-            QueryBuilder::prepare_expr(self, default, sql);
+            // References:
+            // https://sqlite.org/lang_createtable.html
+            sql.write_str(" DEFAULT ").unwrap();
+            match default {
+                Expr::Value(_) | Expr::Constant(_) | Expr::Keyword(_) => {
+                    self.prepare_expr(default, sql)
+                }
+                _ => {
+                    sql.write_str("(").unwrap();
+                    self.prepare_expr(default, sql);
+                    sql.write_str(")").unwrap()
+                }
+            }
         }
 
         if let Some(generated) = generated {

tests/sqlite/table.rs

@@ -515,3 +515,23 @@ fn alter_with_named_check_constraint() {
         r#"ALTER TABLE "glyph" ADD COLUMN "aspect" integer NOT NULL DEFAULT 101 CONSTRAINT "positive_aspect" CHECK ("aspect" > 100)"#,
     );
 }
+
+#[test]
+fn create_default_parentheses_for_expression() {
+    assert_eq!(
+        Table::create()
+            .table(Glyph::Table)
+            .col(
+                ColumnDef::new(Glyph::Aspect)
+                    .integer()
+                    .default(Expr::val(1).add(1)),
+            )
+            .to_string(SqliteQueryBuilder),
+        [
+            r#"CREATE TABLE "glyph" ("#,
+            r#""aspect" integer DEFAULT (1 + 1)"#,
+            r#")"#,
+        ]
+        .join(" "),
+    );
+}