Thread: Please help me to slove this SQL statements
There are three table in database which is suppliers, projects, and shipments suppliers contain suppliers id, name ...etc projects contain project name ..suppliers ID ( J1---J7) ...etc shipments table contain suppliers ID , PROJECTS ID how can i query to find out the suppliers to supply all the projects ID
-----Message d'origine----- De : Freshman [mailto:abc@msn.com] Envoyé : jeudi 30 octobre 2003 13:38 À : pgsql-sql@postgresql.org Objet : [SQL] Please help me to slove this SQL statements There are three table in database which is suppliers, projects, and shipments suppliers contain suppliers id, name ...etc projects contain project name ..suppliers ID ( J1---J7) ...etc shipments table contain suppliers ID , PROJECTS ID how can i query to find out the suppliers to supply all the projects ID I would suggest: SELECT * from suppliers WHERE NOT EXISTS(SELECT * FROM projectsWHERE NOT EXISTS( SELECT * from shipments WHERE shipments.suppliers_ID = suppliers_suppliers_id AND shipments.project_ID = project.project_id) ); so you select every supplier who didn't miss any project. Is that you want to do? ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match