message: change || to concat to deal with NULL strings, and change row_number() to rowid
diff: @@ -37,7 +37,7 @@ static string indexing_script(string input_schema, string input_table, string in
  CREATE TABLE %fts_schema%.docs AS (
  SELECT
  - row_number() OVER (PARTITION BY(SELECT NULL)) AS docid,
  + rowid + 1 AS docid,
  %input_id% AS name
  FROM
  %input_schema%.%input_table%
  @@ -51,7 +51,7 @@ static string indexing_script(string input_schema, string input_table, string in
  FROM (
  SELECT
  %fts_schema%.tokenize(%input_values%) AS term,
  - row_number() OVER (PARTITION BY (SELECT NULL)) AS docid
  + rowid + 1 AS docid
  FROM %input_schema%.%input_table%
  ) AS sq
  WHERE
  @@ -139,7 +139,7 @@ static string indexing_script(string input_schema, string input_table, string in
  result = StringUtil::Replace(result, "%input_schema%", input_schema);
  result = StringUtil::Replace(result, "%input_table%", input_table);
  result = StringUtil::Replace(result, "%input_id%", input_id);
  - result = StringUtil::Replace(result, "%input_values%", StringUtil::Join(input_values, " || ' ' || "));
  + result = StringUtil::Replace(result, "%input_values%", StringUtil::Format("concat(%s)", StringUtil::Join(input_values, ", ' ', ")));
  result = StringUtil::Replace(result, "%stemmer%", stemmer);
  return result;
  