Casting
Certain data types can be cast to and from other types implicitly or explicitly.
- 🟢 Implicit: Values can be automatically converted to the target type.
- 🟠 Assignment: Values can be automatically converted when inserted to a column of the target type.
- 🔷 Explicit: Values can be converted to the target type only when you use the
castfunction or the::operator.
| From \ To | boolean | smallint | integer | bigint | numeric | real | double | varchar | date | timestamp | timestamp with time zone | time | interval |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| boolean | ✖️ | 🔷 | ✖️ | ✖️ | ✖️ | ✖️ | 🟠 | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | |
| smallint | ✖️ | 🟢 | 🟢 | 🟢 | 🟢 | 🟢 | 🟠 | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | |
| integer | 🔷 | 🟠 | 🟢 | 🟢 | 🟢 | 🟢 | 🟠 | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | |
| bigint | ✖️ | 🟠 | 🟠 | 🟢 | 🟢 | 🟢 | 🟠 | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | |
| numeric | ✖️ | 🟠 | 🟠 | 🟠 | 🟢 | 🟢 | 🟠 | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | |
| real | ✖️ | 🟠 | 🟠 | 🟠 | 🟠 | 🟢 | 🟠 | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | |
| double | ✖️ | 🟠 | 🟠 | 🟠 | 🟠 | 🟠 | 🟠 | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | |
| varchar | 🔷 | 🔷 | 🔷 | 🔷 | 🔷 | 🔷 | 🔷 | 🔷 | 🔷 | 🔷 | 🔷 | 🔷 | |
| date | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | 🟠 | 🟢 | 🟢 | ✖️ | ✖️ | |
| timestamp | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | 🟠 | 🟠 | 🟢 | 🟠 | ✖️ | |
| timestamp with time zone | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | 🟠 | 🟠 | 🟠 | 🟠 | ✖️ | |
| time | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | 🟠 | ✖️ | ✖️ | ✖️ | 🟢 | |
| interval | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | ✖️ | 🟠 | ✖️ | ✖️ | ✖️ | 🟠 |
note
Structs can be casted to structs explictly or implicitly if the nested expressions and types can be casted.
