PostgreSQL 8.2.3 婺桺桺懼
劯锔	媆锔		媆誕	嬉誕

䆹9. 庘昄启淉嘩严

䕞嘘

9.9.1. EXTRACT, date_part
9.9.2. date_trunc
9.9.3. AT TIME ZONE
9.9.4. 嘷嬉斖橘/施閘
9.9.5. 傽施欓臯

9.10. 庹嘘庘昄启淉嘩严

9.11. 䘏䂩婄应庘昄启淉嘩严

9.12. 废彖淉嘩庘昄

9.13. 溇傽臘膆嚟

9.13.1. CASE
9.13.2. COALESCE
9.13.3. NULLIF
9.13.4. GREATEST 启 LEAST

9.14. 昄䂇庘昄启淉嘩严

9.15. 蕔镖庘昄

9.16. 床昖臵臘膆嚟

9.16.1. EXISTS
9.16.2. IN
9.16.3. NOT IN
9.16.4. ANY/SOME
9.16.5. ALL
9.16.6. 锊臯懫膄

9.17. 臯启昄䂇懫膄

9.17.1. IN
9.17.2. NOT IN
9.17.3. ANY/SOME (昄䂇)
9.17.4. ALL (昄䂇)
9.17.5. 锊臯懫膄

9.18. 誫啂镖劽䔇庘昄

9.19. 係䂘媇敇庘昄

9.20. 係䂘䞇䊖庘昄

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劯锔	饡釕	嬉誕
XML桺懼櫇毕	婪婔亓	锂膏淉嘩严