Res judicata operates as a bar to maintaining a second suit between the same parties or parties in privity with them on the same cause of action. (Branson v. Sun-Diamond Growers (1994) 24 Cal. App. 4th 327, 340 [29 Cal. Rptr. 2d 314].) For purposes of res judicata, California applies the primary right theory to define cause of action as: (1) a primary right possessed by the plaintiff; (2) a corresponding duty imposed upon the defendant; (3) a wrong done by the defendant which is a breach of such primary right and duty. (Slater v. Blackwood (1975) 15 Cal. 3d 791, 795 [126 Cal. Rptr. 225, 543 P.2d 593]; Lucas v. County of Los Angeles (1996) 47 Cal. App. 4th 277, 285-286 [54 Cal. Rptr. 2d 655].) Thus, a single cause of action is based on the harm suffered, rather than on the particular legal theory asserted or relief sought by the plaintiff. (Agarwal v. Johnson (1979) 25 Cal. 3d 932, 954-955 [160 Cal. Rptr. 141, 603 P.2d 58], disapproved on another ground in White v. Ultramar, Inc. (1999) 21 Cal. 4th 563, 574, fn. 4 [88 Cal. Rptr. 2d 19, 981 P.2d 944]; Slater v. Blackwood, supra, 15 Cal. 3d at p. 795.) "Where, as here, an action is filed in a California state court and the defendant claims the suit is barred by a final federal judgment, California law will determine the res judicata effect of the prior federal court judgment on the basis of whether the federal and state actions involve the same primary right." (Gamble v. General Foods Corp. (1991) 229 Cal. App. 3d 893, 898 [280 Cal. Rptr. 457].) When the doctrine of res judicata refutes all triable issues of fact suggested by the pleadings, summary judgment is proper. (Ibid.)