fix: change the way the comma appears in the column SQL creation to fix a SQL syntax error

src/query_builders/column_sql_serializer.rs

@@ -46,8 +46,7 @@ impl ColumnSqlSerializer {
             query += "PRIMARY KEY ";
         }
 
-        query.push(',');
-        Ok(query)
+        Ok(query.trim_end().to_string())
     }
 }
 
@@ -70,7 +69,7 @@ mod tests {
         let serializer = ColumnSqlSerializer{};
         let result = serializer.serialize(column).unwrap();
 
-        assert_eq!(result, "id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY ,".to_string());
+        assert_eq!(result, "id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY".to_string());
     }
 
     #[test]
@@ -85,7 +84,7 @@ mod tests {
         let serializer = ColumnSqlSerializer{};
         let result = serializer.serialize(column).unwrap();
 
-        assert_eq!(result, "name TEXT NOT NULL DEFAULT 'None' ,".to_string());
+        assert_eq!(result, "name TEXT NOT NULL DEFAULT 'None'".to_string());
     }
 
     #[test]
@@ -100,6 +99,6 @@ mod tests {
         let serializer = ColumnSqlSerializer {};
         let result = serializer.serialize(column).unwrap();
 
-        assert_eq!(result, "age INTEGER NOT NULL DEFAULT 18 ,".to_string());
+        assert_eq!(result, "age INTEGER NOT NULL DEFAULT 18".to_string());
     }
 }

src/query_builders/table_sql_serializer.rs

@@ -6,16 +6,13 @@ pub struct TableSqlSerializer {}
 
 impl TableSqlSerializer {
     pub fn serialize(self, table: Table) -> String {
-        let mut query = String::from("CREATE TABLE ");
-        query += &format!("{} (\n", table.name);
-        
         let column_serializer = ColumnSqlSerializer{};
-        for column in table.columns {
-            query += &column_serializer.serialize(column).unwrap();
-        }
+        let columns_sql: Vec<String> = table.columns
+            .into_iter()
+            .map(|c| column_serializer.serialize(c).unwrap())
+            .collect();
 
-        query += ");";
-        query
+        format!("CREATE TABLE {} ({});", table.name, columns_sql.join(", "))
     }
 }
 
@@ -43,6 +40,6 @@ mod test {
 
         let result = serializer.serialize(table);
 
-        assert_eq!(result, "CREATE TABLE test (\nid INTEGER NOT NULL AUTO_INCREMENT ,);".to_string());
+        assert_eq!(result, "CREATE TABLE test (id INTEGER NOT NULL AUTO_INCREMENT);".to_string());
     }
 }