In SQL Server you can use CAST function to convert an expression to another data type. In Oracle you can also use CAST function but data types can be different.
SQL Server:
-- Convert number to string SELECT CAST(123.45 AS VARCHAR(6));
Oracle:
-- Convert number to string SELECT CAST(123.45 AS VARCHAR2(6)) FROM dual;
Note that the SQL Server and Oracle CAST functions round decimal values if the precision of an input expression exceeds the target data type precision.
SQL Server:
-- Rounding up during conversion SELECT CAST('123.45' AS DECIMAL(5,1)) /* 123.5 */ -- Rounding down SELECT CAST('123.43' AS DECIMAL(5,1)) /* 123.4 */
Oracle:
-- Rounding up during conversion SELECT CAST('123.45' AS NUMBER(5,1)) FROM dual; /* 123.5 */ -- Rounding down SELECT CAST('123.43' AS NUMBER(5,1)) FROM dual; /* 123.4 */
For more information, see SQL Server to Oracle Migration.