Question

I have the following tables:

Table_1:

Value_ID     Value_Code_1      Value_Code_2       Value_Code_3
1            465               325                129

Table_2:

ID          Text
465         this is a value
325         this value is a different one
129         hello world

I need to replace the codes in Table_1 with the Text from Table_2. The way I thought about solving it seems quite long and hairy, is there a quicker, better way of doing this? I have to do this for around 40 columns and not 3 as in my example.

My code:

Select
    first.ID,
    first.string_value,
    second.string_value,
    third.string_value
from
(
    Select
        a.ID,
        b.text as string_value
    From
        table_1 a
        left join
        table_2 b
        on a.Value_Code_1 = b.ID
) first

left join on first.id = second.id

(
    Select
        a.ID,
        b.text as string_value
    From
        table_1 a
        left join
        table_2 b
        on a.Value_Code_2 = b.ID
) second

left join on first.id = third.id
(
    Select
        a.ID,
        b.text as string_value
    From
        table_1 a
        left join
        table_2 b
        on a.Value_Code_2 = b.ID
) third

Thank you.

Answer 1

You can do it simpler, like this:

Select
    Table_1.ID,
    v1.Text,
    v2.Text,
    v3.Text
FROM Table_1
LEFT JOIN Table_2 v1 ON Table_1.Value_code_1 = v1.id
LEFT JOIN Table_2 v2 ON Table_1.Value_code_2 = v2.id
LEFT JOIN Table_2 v3 ON Table_1.Value_code_3 = v3.id;

You still need to do it for all 40 columns.