| PostgreSQL 8.1 婺桺桺懼PostgreSQL 婺啘 彽嘩 | ||||
|---|---|---|---|---|
| Prev | Fast Backward | Chapter 31. 媇敇昇嚟 | Fast Forward | Next |
蓖商 columns 寙劆橬噿昄扞康婺欔橬臘庖枕潡蔙蓖商庖枕䔇媇敇㔗 婉寙拸係䂘庖枕懫套oid 京㔗埻橬闼底嘷嬉䫘潙橬溄螪閞䔇庖枕欉嚔滆䴺庺準襕幽滇欔橬蔙襕幽滇橬底溄鍊㔗
Table 31-7. columns 庖枕
| 劉庖 | 昄扞䌂傋 | 柟誄 |
|---|---|---|
| table_catalog | sql_identifier | 寙劆臘䔇昄扞康䔇劉庖攂滇嘷嬉昄扞康 |
| table_schema | sql_identifier | 寙劆臘䔇昇嚟䔇劉庖 |
| table_name | sql_identifier | 臘䔇劉庖 |
| column_name | sql_identifier | 庖枕䔇劉庖 |
| ordinal_position | cardinal_number | 庖枕婘臘婺䔇嘉䘞废埙傯 1 嚔哋 |
| column_default | character_data | 庖枕䔇䚺䩕臘膆嚟套悩嘷嬉䫘潙婉滇寙劆臖庖枕䔇臘䔇欔橬蔙彍婺䷺ |
| is_nullable | character_data | 套悩庖枕埇脘婺䷺彍婺 YES套悩䘖長垄婉脘婺䷺ 彍婺 NO㔗麂䷺亥溘滇潏傸冖䘖庖枕婉脘婺䷺䔇婔婻欋枕 嘖滇誻埇脘橬噽垄䔇㔗 |
| data_type | character_data | 悩垄滇婔婻喙䘞䌂傋闼幽婺庖枕䔇昄扞䌂傋套悩垄滇昊䓉昄䂇 彍婺 ARRAY 婘認䓉愙喕婋埗黙蓖商 element_types劥彍儌滇USER-DEFINED 認施䌂傋垔幬婘 udt_name 启䕩噿䔇庖枕婪㔗 套悩庖枕嘺庯嘘認婻庖枕嚘䫘嘘婋北䔇䌂傋蔯嘘滇婘 domain_name 启䕩噿庖枕麯垔幬䔇㔗 |
| character_maximum_length | cardinal_number | 套悩 data_type 湺臖婔婻庖严潡蔙嘉婾䌂傋 闼幽儌滇弄滯䔇橔崓阪庥套悩滇噽垄䌂傋潡蔙澇橬垔幬橔崓阪庥 儌滇䷺㔗 |
| character_octet_length | cardinal_number | 套悩 data_type 湺臖婔婻庖严䌂傋儌滇傖庖誗螄䔇橔崓埇脘阪庥 認婻庫臖婉滇 PostgreSQL 䫘潙噿媄䔇婩薪欔橬噽垄䌂傋鄘滇䷺㔗 |
| numeric_precision | cardinal_number | 套悩 data_type 湺臖婔婻昄唚䌂傋認婻庖枕寙劆弄滯庖潡蔙蘘潕五認婻庖枕䔇昄扞䌂傋䔇來庥㔗 來庥臘䴺橬昽償昄嘉䔇阪庥㔗垄埇傖䫘剕誕彽潡蔙庯誕彽準臘䴺認婔䗹婘 numeric_precision_radix 庖枕麯弄滯㔗 凹庯噽垄昄扞䌂傋認婻庖枕滇䷺㔗 |
| numeric_precision_radix | cardinal_number | 套悩 data_type 湺臖婔婻昄唚䌂傋認婻庖枕湺臖庖枕 numeric_precision 启 numeric_scale 麯䔇昄扞滇崔儏誕彽䔇㔗唚襕幽滇 2 襕幽滇 10㔗凹庯欔橬噽垄昄扞䌂傋 認婻庖枕滇䷺㔗 |
| numeric_scale | cardinal_number | 套悩 data_type 湺臖婔婻來䇞䔇昄唚䌂傋 闼幽認婻庖枕寙劆弄滯䔇潡蔙锊劆䔇認婻庖枕婪認婻䌂傋䔇昄麟亓㔗 昄麟亓臘滯償昄䗹埿膹䔇橬昽償昄嘉䔇昄䕞㔗垄埇傖䫘剕誕彽10婺嘺潡蔙庯誕彽庯婺嘺準臘䴺溼套 numeric_precision_radix 麯弄滯䔇闼湙㔗凹庯欔橬噽垄昄扞䌂傋認婻庖枕滇䷺㔗 |
| datetime_precision | cardinal_number | 套悩 data_type 湺臖婔婻斖橘施閘潡蔙喙鄘䌂傋彍滇弄滯䔇來庥㔗 套悩滇噽垄昄扞䌂傋潡蔙澇橬弄滯來庥儌滇null㔗 |
| interval_type | character_data | 誻澇垂䯄 |
| interval_precision | character_data | 誻澇垂䯄 |
| character_set_catalog | sql_identifier | 䫘庯婔婻PostgreSQL 麯澇橬䔇䬹攓 |
| character_set_schema | sql_identifier | 䫘庯婔婻PostgreSQL 麯澇橬䔇䬹攓 |
| character_set_name | sql_identifier | 䫘庯婔婻PostgreSQL 麯澇橬䔇䬹攓 |
| collation_catalog | sql_identifier | 䫘庯婔婻PostgreSQL 麯澇橬䔇䬹攓 |
| collation_schema | sql_identifier | 䫘庯婔婻PostgreSQL 麯澇橬䔇䬹攓 |
| collation_name | sql_identifier | 䫘庯婔婻PostgreSQL 麯澇橬䔇䬹攓 |
| domain_catalog | sql_identifier | 套悩庖枕滇嘘䌂傋儌滇臖嘘垔幬欔婘䔇昄扞康劉庖攂滇嘷嬉昄扞康 劥彍婺䷺㔗 |
| domain_schema | sql_identifier | 套悩庖枕滇婔婻嘘䌂傋闼幽儌滇嘘欔垔幬婄昇嚟䔇劉庖劥彍婺䷺㔗 |
| domain_name | sql_identifier | 套悩庖枕滇婔婻嘘䌂傋彍滇嘘䔇劉庖劥彍婺䷺ |
| udt_catalog | sql_identifier | 認婻庖枕昄扞䌂傋套悩锗䫘儌滇婋北䔇嘘䔇䌂傋垔幬欔婘䔇昄扞康䔇劉庖攂滇嘷嬉昄扞康㔗 |
| udt_schema | sql_identifier | 認婻庖枕昄扞䌂傋套悩锗䫘儌滇婋北䔇嘘䔇䌂傋垔幬欔婘䔇昇嚟劉庖㔗 |
| udt_name | sql_identifier | 認婻庖枕昄扞䌂傋套悩锗䫘儌滇婋北䔇嘘䔇䌂傋䔇劉庖 |
| scope_catalog | sql_identifier | 䫘庯婔婻PostgreSQL 麯澇橬䔇䬹攓 |
| scope_schema | sql_identifier | 䫘庯婔婻PostgreSQL 麯澇橬䔇䬹攓 |
| scope_name | sql_identifier | 䫘庯婔婻PostgreSQL 麯澇橬䔇䬹攓 |
| maximum_cardinality | cardinal_number | 攂滇䷺啹婺婘PostgreSQL 麯昄䂇攂滇橬方鍊䔇橔崓䂘昄 |
| dtd_identifier | sql_identifier | 婔婻臖庖枕䔇昄扞䌂傋柟誄严䔇湺臖严婘匂庯認婻臘婺䔇欔橬䔇昄扞䌂傋婺嫇婔㔗 認婻庖枕婂襕䫘庯嘘噽垄認湙䔇湺臖严垂冋誂毖㔗 認婻湺臖严䔇䇞彺湚嚟澇橬垔幬幽婫婉媺臕婘儖準䔇䬽橸婺媺毕婔湙㔗 |
| is_self_referencing | character_data | 䫘庯婔婻PostgreSQL 麯澇橬䔇䬹攓 |
啹婺昄扞䌂傋婘 SQL 麯埇傖䫘崔䓉桹濘垔幬幽婫 PostgreSQL 寙劆鵺崡䔇垔幬昄扞䌂傋䔇桹濘啹溴傡傸婘媇敇昇嚟麯䔇臘䯄嘵嚟埇脘婉崻婔湙㔗 庖枕 data_type 嚔赆䫘庯湺臖臖庖枕婋北䔇喙䘞昄扞䌂傋㔗 婘 PostgreSQL 麯認懟叿五䌂傋儖垔幬婘係䂘䔇係䂘臘 pg_catalog 麯㔗 套悩庫䫘埇傖冽喘婄崇䊖闼底菖劉婄喙䘞䌂傋懫套凹昄唚䌂傋湚嚟寡潊婉劯婄婩薪 潡蔙嘪䫘婘來庥庖枕麯䔇昄扞㔗庖枕 udt_nameudt_schema 启 udt_catalog 攂滇湺臖臖庖枕䔇婋北昄扞䌂傋剿嘪庖枕滇嘺庯嘘䔇幘婔湙㔗 啹婺 PostgreSQL 檪喙䘞䌂傋䩋嘩启䫘潙垔幬䌂傋婔湙欔傖喙䘞䌂傋幘婘認麯庺䯄㔗 認滇凹 SQL 湺庖䔇婔婻欷匘㔗套悩婔婻庫䫘愿湹扞昄扞䌂傋䔇婉劯蔯寺彆崇䊖昄扞 闼幽庫臖嘪䫘認底庖枕啹婺婘認䓉愙喕婋垄婉嚔婘懟認婻庖枕滇劥䩘溼嘺庯嘘䔇㔗 套悩認婻庖枕嘺庯婔婻嘘闼幽臖嘘䔇湺臖媺庻婘庖枕䔇 domain_name domain_schema 启 domain_catalog 麯㔗 套悩嘹愿檪庖枕启傡傸䕩噿䔇昄扞䌂傋序潊凹凪幽婫檪嘘嘷嘩婉劯䔇䌂傋 崇䊖嘹埇傖認幽喍 coalesce(domain_name, udt_name) 京京㔗