The relational schema below represents the POP schema. JOURNALS(j_num, j_name, j

Question

The relational schema below represents the POP schema. JOURNALS(j_num, j_name, j_subject_area, chief_editor_r_ ssn') lSSUES(j_num, i_num, i_date, i_num_pages) RESEARCHERS(r_ssn, r_name, r_address, r_phone, r_institution) ARTICLES(art_num, art_title, art_area_topic, art_abstract, j_num submitted, date_submitted, j_num_published, i_num_published) AREA_EDITS(j_num, r_ssn) WRITES(r_ssn, art_num) REVlEWS(r_ssn, art_num) RESEARCHER_SPECIALITIES(r_spec_name) RRS(r_ssn, r_spec_name) Please formulate the following in SQL: The journal name(s) of the journal(s) with the fewest area editors. The average number of journals that a researcher at 'TU' area-edits. The name of the most popular area topic (the area topic associated with the most articles). The title(s) of the paper(s) with the second highest number of authors. The chief_editor_r_ssn is the r_ssn of the researcher who is chief editor for the journal.

Explanation / Answer

1: select j.j_name from JOURNALS j,AREA_EDITS a where j.j_num=a.j_num;

2: select avg(s.i_num) from JOURNALS s,AREA_EDITS n where s.i_num=n.i_num;

3: select a.art_area_topic from ARTICLES a,AREA_EDITS b,WRITES w where a.art_num=w.art_num and w.r_ssn=b.r_ssn;

4: select a.art_tittle from ARTICLE a,WRITES w where a.art_num=(select a.art_title from  ARTICLE a,WRITES w where a.art_num=(select a.art_title from  ARTICLE a,WRITES w where a.art_num=w.art_num));

thank you

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