oracle常用函数：TO_NUMBER

Converts a string to the NUMBER data type	TO_NUMBER([, , ]) RETURN NUMBER
	CREATE TABLE test ( testcol VARCHAR2(10)); INSERT INTO test VALUES ('12345.67'); SELECT TO_BINARY_DOUBLE(testcol) BIN_DOUBLE, TO_BINARY_FLOAT(testcol) BIN_FLOAT, TO_NUMBER(testcol) NMBR FROM test;
Converts a HEX number to FLOAT	TO_NUMBER(, );
	SELECT TO_NUMBER('0A', 'XX') FROM dual;
Converts a HEX number to DECIMAL	TO_NUMBER(, '') RETURN ;
	SELECT TO_NUMBER(100000,'XXXXXXXX') FROM dual;