{"Entry":{"collection":"protocol","key":"parameterdescription-b","name":"ParameterDescription","aliases":["ParameterDescription","Byte1('t')"],"metadata":{"aliases":["ParameterDescription","Byte1('t')"],"category":"Backend messages","content_hash":"0ff6d2d6dc8aec209913b0ecca85b83e8411faf18bf1d3f631ac071dfff8d151","derived_content_hash":"0ada3d8469c74b40c9b3892a6462809992b147fdb440b326731fac0d9bf45676","imported_at":"2026-09-30T00:40:44.491878+08:00","name":"ParameterDescription","name_zh":"","slug":"parameterdescription-b","summary":"ParameterDescription is a backend protocol message. Identifies the message as a parameter description."}},"Definition":{"Collection":"protocol","Key":"parameterdescription-b","SourceDatabase":"center","Version":"18","SourceTable":"protocol_message","SourceKey":"parameterdescription-b","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","Facts":{"comparison_data":{"direction":"B","fields":[{"description":"Identifies the message as a parameter description.","format":"Byte1('t')"},{"description":"Length of message contents in bytes, including self.","format":"Int32"},{"description":"The number of parameters used by the statement (can be zero).","format":"Int16"},{"description":"Specifies the object ID of the parameter data type.","format":"Int32"}]},"comparison_hash":"4c97d55c0220c0daca280eccc6c33c5fc76571485d549a71e34f97327c2570ef","description":["ParameterDescription is a backend protocol message. Identifies the message as a parameter description."],"description_zh":"Byte1('t') 标识消息为参数描述。 Int32 消息内容的长度（以字节为单位），包括其自身。 Int16 语句使用的参数数量（可以为零）。 接下来，每个参数都有以下内容： Int32 指定参数数据类型的对象 ID。","description_zh_html":"\u003cp\u003e协议消息 ParameterDescription (B)。\u003c/p\u003e\u003ch3\u003e同版本中文手册定义\u003c/h3\u003e\u003cdd\u003e\u003cdiv class=\"variablelist\"\u003e\u003cdl class=\"variablelist\"\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('t')\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         标识消息为参数描述。\n        \u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         消息内容的长度（以字节为单位），包括其自身。\n        \u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eInt16\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         语句使用的参数数量（可以为零）。\n        \u003c/p\u003e\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e\u003cp\u003e\n      接下来，每个参数都有以下内容：\n     \u003c/p\u003e\u003cdiv class=\"variablelist\"\u003e\u003cdl class=\"variablelist\"\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n         指定参数数据类型的对象 ID。\n        \u003c/p\u003e\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e\u003c/dd\u003e\u003cp\u003e\u003ca href=\"/zh/docs/18/protocol-message-formats.html#PROTOCOL-MESSAGE-FORMATS-PARAMETERDESCRIPTION\"\u003e查看完整中文手册与上下文\u003c/a\u003e。\u003c/p\u003e","direction":"B","facts":[{"label":"Direction","value":"Backend → frontend"},{"label":"First wire field","value":"Byte1('t')"},{"label":"Field entries","value":"4"},{"label":"Documented flow contexts","value":"Extended Query"}],"facts_zh":[{"label":"方向","value":"后端 → 前端"},{"label":"首个线上协议字段","value":"Byte1('t')"},{"label":"字段条目","value":"4"},{"label":"手册中的交互阶段","value":"扩展查询"}],"fields":[{"description":"Identifies the message as a parameter description.","format":"Byte1('t')"},{"description":"Length of message contents in bytes, including self.","format":"Int32"},{"description":"The number of parameters used by the statement (can be zero).","format":"Int16"},{"description":"Specifies the object ID of the parameter data type.","format":"Int32"}],"manual_html":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('t')\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a parameter description.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eLength of message contents in bytes, including self.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt16\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe number of parameters used by the statement (can be zero).\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eThen, for each parameter, there is the following:\u003c/p\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eSpecifies the object ID of the parameter data type.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003c/dd\u003e\u003c/dl\u003e","manual_path":"/docs/18/protocol-message-formats.html","related":[{"label":"Protocol flow and exchange examples","url":"/docs/18/protocol-flow.html"},{"label":"Protocol overview","url":"/docs/18/protocol-overview.html"},{"label":"Extended Query","url":"/docs/18/protocol-flow.html#PROTOCOL-FLOW-EXT-QUERY"}],"release":{"channel":"stable","label":"18.6","major":"18","ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sections":[{"paragraphs":["The complete definition below retains repetition, counts and conditional fields. A numbered table row is a documented field definition, not a fixed byte offset. Integer encodings and flow rules follow the same-version protocol chapter."],"title":"Framing and repetition"}],"sections_zh":[{"paragraphs":["下方完整定义保留重复项、计数与条件字段。表格行号表示文档中的字段定义，并非固定字节偏移量。整数编码与交互流程以同版本协议章节为准。"],"title":"消息边界与重复字段"}],"signature":"ParameterDescription (B)","sources":[{"label":"PostgreSQL 18 English manual","path":"protocol-message-formats.html","sha256":"53f37652ac2c089e30ada87d8aee7bdd0f26695b03f275302e526a807d2a1f23","url":"/docs/18/protocol-message-formats.html#PROTOCOL-MESSAGE-FORMATS-PARAMETERDESCRIPTION"}],"tables":[{"columns":[{"key":"c0","label":"Position"},{"key":"c1","label":"Format"},{"key":"c2","label":"Meaning"}],"key":"fields","rows":[{"c0":"1","c1":"Byte1('t')","c2":"Identifies the message as a parameter description."},{"c0":"2","c1":"Int32","c2":"Length of message contents in bytes, including self."},{"c0":"3","c1":"Int16","c2":"The number of parameters used by the statement (can be zero)."},{"c0":"4","c1":"Int32","c2":"Specifies the object ID of the parameter data type."}],"title":"Wire fields in documented order"}],"tables_zh":[{"columns":[{"key":"c0","label":"位置"},{"key":"c1","label":"格式"},{"key":"c2","label":"含义"}],"key":"fields","rows":[{"c0":"1","c1":"Byte1('t')","c2":"标识消息为参数描述。"},{"c0":"2","c1":"Int32","c2":"消息内容的长度（以字节为单位），包括其自身。"},{"c0":"3","c1":"Int16","c2":"语句使用的参数数量（可以为零）。"},{"c0":"4","c1":"Int32","c2":"指定参数数据类型的对象 ID。"}],"title":"按手册顺序排列的线上协议字段"}],"zh_from":{"authored_translation":"source-derived-identity","body_sha256":"a902cc3ef81d56d5b4f8d81831f0e4005bd8dce04797accfe0eb5ed85e5cc059","kind":"same-version-chinese-manual-with-source-derived-identity","manual":{"anchor":"PROTOCOL-MESSAGE-FORMATS-PARAMETERDESCRIPTION","build_id":107,"extraction":"exact-definition","fragment_sha256":"1137298b258ccdcb1ca485ebb7eca0ea9699e49b404247fb27e855f5bb6614d2","locale":"zh-Hans","page_key":"protocol-message-formats.html","source_hash":"0be0a37b38d80c96c157ca9fcfe9222995654664aad8136f7ac2b1b552f6753a","source_revision":"unknown:rendered-translation-baseline","translated_from_revision":null,"translation_revision":"git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:08e987a66af27b98444a8057c256314eafa13611a3fb9e888214fc436824244b","url":"/zh/docs/18/protocol-message-formats.html#PROTOCOL-MESSAGE-FORMATS-PARAMETERDESCRIPTION","version":"18"},"runtime_rerun":false,"source_facts_revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}},"ManualEvidence":{"manual_path":"/docs/18/protocol-message-formats.html","release":{"channel":"stable","label":"18.6","major":"18","ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sources":[{"label":"PostgreSQL 18 English manual","path":"protocol-message-formats.html","sha256":"53f37652ac2c089e30ada87d8aee7bdd0f26695b03f275302e526a807d2a1f23","url":"/docs/18/protocol-message-formats.html#PROTOCOL-MESSAGE-FORMATS-PARAMETERDESCRIPTION"}]},"MeasuredEvidence":{}},"Text":{"Collection":"protocol","Key":"parameterdescription-b","SourceDatabase":"center","Version":"18","Locale":"en","Title":"ParameterDescription","Summary":"ParameterDescription is a backend protocol message. Identifies the message as a parameter description.","BodyHTML":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv\u003e\n\u003cdl\u003e\n\u003cdt\u003e\u003cspan\u003eByte1(\u0026#39;t\u0026#39;)\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a parameter description.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eLength of message contents in bytes, including self.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan\u003eInt16\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe number of parameters used by the statement (can be zero).\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eThen, for each parameter, there is the following:\u003c/p\u003e\n\u003cdiv\u003e\n\u003cdl\u003e\n\u003cdt\u003e\u003cspan\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eSpecifies the object ID of the parameter data type.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003c/dd\u003e\u003c/dl\u003e","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","ContentHash":"9b8c902d913d120f0854b347ec8079d599a5f0a312a1e45c1cab554c9d9b7ad2","Payload":{"description":["ParameterDescription is a backend protocol message. Identifies the message as a parameter description."],"manual_html":"\u003cdl\u003e\u003cdd\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eByte1('t')\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eIdentifies the message as a parameter description.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eLength of message contents in bytes, including self.\u003c/p\u003e\n\u003c/dd\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt16\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eThe number of parameters used by the statement (can be zero).\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cp\u003eThen, for each parameter, there is the following:\u003c/p\u003e\n\u003cdiv class=\"variablelist\"\u003e\n\u003cdl class=\"variablelist\"\u003e\n\u003cdt\u003e\u003cspan class=\"term\"\u003eInt32\u003c/span\u003e\u003c/dt\u003e\n\u003cdd\u003e\n\u003cp\u003eSpecifies the object ID of the parameter data type.\u003c/p\u003e\n\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003c/dd\u003e\u003c/dl\u003e","related":[{"label":"Protocol flow and exchange examples","url":"/docs/18/protocol-flow.html"},{"label":"Protocol overview","url":"/docs/18/protocol-overview.html"},{"label":"Extended Query","url":"/docs/18/protocol-flow.html#PROTOCOL-FLOW-EXT-QUERY"}],"sections":[{"paragraphs":["The complete definition below retains repetition, counts and conditional fields. A numbered table row is a documented field definition, not a fixed byte offset. Integer encodings and flow rules follow the same-version protocol chapter."],"title":"Framing and repetition"}],"tables":[{"columns":[{"key":"c0","label":"Position"},{"key":"c1","label":"Format"},{"key":"c2","label":"Meaning"}],"key":"fields","rows":[{"c0":"1","c1":"Byte1('t')","c2":"Identifies the message as a parameter description."},{"c0":"2","c1":"Int32","c2":"Length of message contents in bytes, including self."},{"c0":"3","c1":"Int16","c2":"The number of parameters used by the statement (can be zero)."},{"c0":"4","c1":"Int32","c2":"Specifies the object ID of the parameter data type."}],"title":"Wire fields in documented order"}]}},"RequestedLocale":"en","Fallback":false,"Versions":["10","11","12","13","14","15","16","17","18","19","20"],"Locales":["en","zh-Hans"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}