CAST converts values from one data type to another.
The data type specified by type_name.
CAST(expr AS type_name)
expr can be an expression in one of the data types.
type_name is one of the data types listed in Table 1-2, "Dimensional Data Types".
Table 3-1 shows which data types can be cast into which other built-in data types. NUMBER includes NUMBER, DECIMAL, and INTEGER. DATETIME includes DATE, TIMESTAMP, TIMESTAMP WITH TIMEZONE, and TIMESTAMP WITH LOCAL TIMEZONE. INTERVAL includes INTERVAL DAY TO SECOND and INTERVAL YEAR TO MONTH.
Table 3-1 Compatible Data Types
| From | To BINARY_FLOAT, BINARY_DOUBLE | To CHAR, VARCHAR2 | To NUMBER | To DATETIME, INTERVAL | To NCHAR, NVARCHAR2 |
|---|---|---|---|---|---|
|
BINARY_FLOAT, BINARY_DOUBLE |
yes |
yes |
yes |
no |
yes |
|
CHAR, VARCHAR2 |
yes |
yes |
yes |
yes |
no |
|
NUMBER |
yes |
yes |
yes |
no |
yes |
|
DATETIME, INTERVAL |
no |
yes |
no |
yes |
yes |
|
NCHAR, NVARCHAR2 |
yes |
no |
yes |
no |
yes |
CAST('123.4567' AS NUMBER(10,2)) returns the value 123.46.