ClickHouse CAST column AS SIGNED?

Question

I have a table with column that contains timezone in format: +00:00 eg.:

tz
+04:30
+02:00
+10:00
-04:00

I can use CAST in MySQL: CAST(tz AS SIGNED) and it will give this result:

CAST(tz AS SIGNED)
4
2
10
-4

I tried to use toInt64 for ClickHouse, but it produce an exception.
How I can reach the same result with ClickHouse ?

Answer 1

SELECT
    arrayJoin(['+04:30', '-4:30', '10:00']) AS x,
    toInt64OrZero(extract(x, '(.*):')) AS y

Query id: 4b704281-649a-499e-906c-89873112c9e1

┌─x──────┬──y─┐
│ +04:30 │  4 │
│ -4:30  │ -4 │
│ 10:00  │ 10 │
└────────┴────┘