oracle 函数数值型字符判断

判断oracle 输入的字符串是否为纯数值型字符串，如'01242342' 则返回0，其他返回1，其他如'243dfsf234','2343s','w24234'等包含非数值型字符的字符创

 

FUNCTION IS_INTEGER(
    IN_VARCHAR IN VARCHAR2)
  RETURN INTEGER AS FLAG INTEGER;
  I INTEGER;
BEGIN
FOR I IN 1..LENGTH(IN_VARCHAR)
LOOP
IF ASCII(SUBSTR(IN_VARCHAR,I,1))>=48 AND ASCII(SUBSTR(IN_VARCHAR,I,1))<=57
THEN
FLAG:=0;
ELSE
FLAG:=-1;
EXIT;
END IF;
END LOOP;
  RETURN FLAG;
  END IS_INTEGER;