  We present a catalog of 5,290 RR Lyrae stars (RRLs) with metallicities
estimated from spectra of the LAMOST Experiment for Galactic Understanding and
Exploration (LEGUE) and the Sloan Extension for Galactic Understanding and
Exploration (SEGUE) surveys. Nearly 70 per cent of them (3,642 objects) also
have systemic radial velocities measured. Given the pulsating nature of RRLs,
metallicity estimates are based on spectra of individual exposures, by matching
them with the synthetic templates. The systemic radial velocities are measured
by fitting the observed velocity as a function of phase assuming an empirical
pulsating velocity template curve. Various tests show that our analyses yield
metallicities with a typical precision of 0.20\,dex and systemic radial
velocities with uncertainties ranging from 5 to 21\,km\,s$^{-1}$ (depending on
the number of radial velocity measurements available for a given star). Based
on the well calibrated near-infrared $PM_{W1}Z$ or $PM_{K_{\rm s}}Z$, and
$M_{V}$-[Fe/H] relations, precise distances are derived for these RRLs.
Finally, we include Gaia DR2 proper motions in our catalog. The catalog should
be very useful for various Galactic studies, especially of the Galactic halo.
