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磞瓃ノ Postgres ず竚ㄧ计

砛计沮篈ノㄧ计锣传Θㄤ闽篈Τㄇ篈闽ㄧ计ㄇㄧ计硄筁笲衡才腹ㄏノゅンいΤ笲衡才腹磞瓃

SQL ㄧ计

¨SQL ㄧ计〃琌パ SQL92 夹非﹚竡篶ンウΤㄧ计妓粂猭琌ぃ暗虏虫ㄧ计ㄓ龟瞷

 5-1. SQL ㄧ计

ㄧ计  磞瓃 ㄒ
COALESCE(list) 獶NULL listい材獶NULL COALESCE(r"le>, c2 + 5, 0)
IFNULL(input,non-NULL substitute) 獶NULL 狦材NULL材把计 IFNULL(c1, 'N/A')
CASE WHEN expr THEN expr [...] ELSE expr END expr 材痷笷Α CASE WHEN c1 = 1 THEN 'match' ELSE 'no match' END

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