Method mapper

packages/sql/src/query/QueryBuilderHelper.ts:113–243

(
    field: string | Raw | RawQueryFragmentSymbol,
    type = QueryType.SELECT,
    value?: any,
    alias?: string | null,
    schema?: string,
  )

    schema?: string,
  ): string;
  mapper(
    field: string | Raw | RawQueryFragmentSymbol,
    type = QueryType.SELECT,
    value?: any,
    alias?: string | null,
    schema?: string,
  ): string | Raw {
    if (isRaw(field)) {
      return raw(field.sql, field.params);
    }

    if (Raw.isKnownFragmentSymbol(field)) {
      return Raw.getKnownFragment(field)!;
    }

    /* v8 ignore next */
    if (typeof field !== 'string') {
      return field;
    }

    const isTableNameAliasRequired = this.isTableNameAliasRequired(type);
    const fields = Utils.splitPrimaryKeys(field);

    if (fields.length > 1) {
      const parts: string[] = [];

      for (const p of fields) {
        const [a, f] = this.splitField(p);
        const prop = this.getProperty(f, a);
        const fkIdx2 = prop?.fieldNames.findIndex(name => name === f) ?? -1;

        if (fkIdx2 !== -1) {
          parts.push(
            this.mapper(
              a !== this.#alias ? `${a}.${prop!.fieldNames[fkIdx2]}` : prop!.fieldNames[fkIdx2],
              type,
              value,
              alias,
            ),
          );
        } else if (prop) {
          parts.push(...prop.fieldNames.map(f => this.mapper(a !== this.#alias ? `${a}.${f}` : f, type, value, alias)));
        } else {
          parts.push(this.mapper(a !== this.#alias ? `${a}.${f}` : f, type, value, alias));
        }
      }

      // flatten the value if we see we are expanding nested composite key
      // hackish, but cleaner solution would require quite a lot of refactoring
      if (fields.length !== parts.length && Array.isArray(value)) {
        value.forEach(row => {
          if (Array.isArray(row)) {
            const tmp = Utils.flatten(row);
            row.length = 0;
            row.push(...tmp);
          }
        });
      }