PostgreSQL Function Parameter - CCH0124/database-system GitHub Wiki

PL/pgSQL 支援三種參數模式:inoutinout。如果沒有明確指定參數,則預設參數採用 in 模式。

IN OUT INOUT
The default (預設) Explicitly specified(明確指定) Explicitly specified(明確指定)
Pass a value to function (將值傳遞給函數) Return a value from a function (從函數回傳一個值) Pass a value to a function and return an updated value.(將值傳遞給函數並傳回更新後的值)
in parameters act like constants (像常數) out parameters act like uninitialized variables (像未初始化變數) inout parameters act like initialized variables (像被初始參數)
Cannot be assigned a value (無法賦值) Must assign a value (必須賦值) Should be assigned a value (應該被賦值)

postgresqltutorial | function-parameters