PostgreSQL copy text type column to text[] array type column

Question

I have two columns, material_size (text type) and material_size_temp (text[] array type).

When I ran UPDATE parts SET material_size_temp[0] = material_size; I would get values like [0:0]={".021 x 2.450"} instead of {".021 x 2.450"}.

How do I clone the text type column to text[] array type column?

• Erwin Brandstetter: Do you want to replace the existing value in material_size_temp (the whole array) or just the first element? Or do you want to prepend the array with the text from material_size?
• John: @ErwinBrandstetter Most rows have data (just a single measurement) and some no data. I was just trying to move the data in to an array.

Answer 1

I was close, unlike JavaScript and PHP it seems PostgreSQL array key numbers start with 1, not 0.

UPDATE parts SET material_size_temp[1] = material_size;