如何在Rails上使用PostgreSQL和Ruby更新数组类型的列

Question

I have a column for a table that was created with following ruby on rails migration

def change    
    add_column :matches, :st_history, :smallint, array: true, default: []
end

on a postresql database. I wish to reset all values of the column back to default. I have tried

Match.update_all(st_history: [])

but this does not change any of the fields. Looking at the api documentation , it states that 'It should receive only values that can be passed as-is to the SQL database', so I suspect that the array is a complex datatype that will not work with a simple update_all command. The database has many millions of rows, so I do not want to update each row individually. What is a fast way of doing this?

Answer 1

您可以尝试创建迁移。并可以提供默认值

update_column :table_name, :col_name, :integer, array: true, null: false, default '{}'

Answer 2

This actually works. Just need to reload.