Method applyMaxRows

src/utils/sql-row-limiter.ts:126–144

* Apply maxRows limit to a SELECT query only * * This method is used by PostgreSQL, MySQL, MariaDB, and SQLite connectors which all support * the LIMIT clause syntax. SQL Server uses applyMaxRowsForSQLServer() instead with TOP syntax. * * For parameterized LIMIT clauses (e.g., LIMIT $

(sql: string, maxRows: number | undefined)

   * to enforce max_rows as a hard cap, since the parameter value is not known until runtime.
   */
  static applyMaxRows(sql: string, maxRows: number | undefined): string {
    if (!maxRows || !this.isSelectQuery(sql)) {
      return sql;
    }

    // If query has a parameterized LIMIT, wrap it in a subquery with maxRows
    // This ensures max_rows is respected even when user provides a large parameter value
    if (this.hasParameterizedLimit(sql)) {
      // Wrap the query: SELECT * FROM (original_query) AS subq LIMIT max_rows
      // Note: Subquery wrapping is safe for PostgreSQL, MySQL, MariaDB, and SQLite
      const trimmed = sql.trim();
      const hasSemicolon = trimmed.endsWith(';');
      const sqlWithoutSemicolon = hasSemicolon ? trimmed.slice(0, -1) : trimmed;
      return `SELECT * FROM (${sqlWithoutSemicolon}) AS subq LIMIT ${maxRows}${hasSemicolon ? ';' : ''}`;
    }

    // For literal LIMIT values, apply the minimum logic
    return this.applyLimitToQuery(sql, maxRows);
  }

  /**
   * Apply maxRows limit to a SELECT query using SQL Server TOP syntax