Cal. Health & Safety Code § 11370

(a) Any person convicted of violating Section 11350, 11351, 11351.5, 11352, 11353, 11355, 11357, 11359, 11360, 11361, 11363, 11366, or 11368, or of committing any offense referred to in those sections, shall not, in any case, be granted probation by the trial court or have the execution of the sentence imposed upon him or her suspended by the court, if he or she has been previously convicted of any offense described in subdivision (c).

(b) Any person who was 18 years of age or over at the time of the commission of the offense and is convicted for the first time of selling, furnishing, administering, or giving a controlled substance which is (1) specified in subdivision (b), (c), (e), or paragraph (1) of subdivision (f) of Section 11054, specified in paragraph (14), (15), or (20) of subdivision (d) of Section 11054, or specified in subdivision (b) or (c) of Section 11055, or (2) which is a narcotic drug classified in Schedule III, IV, or V, to a minor or inducing a minor to use such a controlled substance in violation of law shall not, in any case, be granted probation by the trial court or have the execution of the sentence imposed upon him or her suspended by the court.

(c) Any previous conviction of any of the following offenses, or of an offense under the laws of another state or of the United States which, if committed in this state, would have been punishable as such an offense, shall render a person ineligible for probation or suspension of sentence pursuant to subdivision (a) of this section: (1) Any felony offense described in this division involving a controlled substance specified in subdivision (b), (c), (e), or paragraph (1) of subdivision (f) of Section 11054, specified in paragraph (13), (14), (15), or (20) of subdivision (d) of Section 11054, or specified in subdivision (b) or (c) of Section 11055. (2) Any felony offense described in this division involving a narcotic drug classified in Schedule III, IV, or V.

(d) The existence of any previous conviction or fact which would make a person ineligible for suspension of sentence or probation under this section shall be alleged in the information or indictment, and either admitted by the defendant in open court, or found to be true by the jury trying the issue of guilt or by the court where guilt is established by a plea of guilty or nolo contendere or by trial by the court sitting without a jury.