ORACLE验证字段值是否为数字

--创建测试表
DROP TABLE TEST_TO_NUMBER;
CREATE TABLE TEST_TO_NUMBER
(
ID VARCHAR2(2) PRIMARY KEY,
TEST_VAL VARCHAR2(20) NOT NULL
);

--插入测试数据
INSERT INTO TEST_TO_NUMBER (ID, TEST_VAL) VALUES ('1','123');
INSERT INTO TEST_TO_NUMBER (ID, TEST_VAL) VALUES ('2','0.12');
INSERT INTO TEST_TO_NUMBER (ID, TEST_VAL) VALUES ('3','2.141');
INSERT INTO TEST_TO_NUMBER (ID, TEST_VAL) VALUES ('4','.0.1');
INSERT INTO TEST_TO_NUMBER (ID, TEST_VAL) VALUES ('5','a.213');
INSERT INTO TEST_TO_NUMBER (ID, TEST_VAL) VALUES ('6','1..2');
INSERT INTO TEST_TO_NUMBER (ID, TEST_VAL) VALUES ('7','1a1');

--创建验证方法
CREATE OR REPLACE FUNCTION IS_NUMBER (IN_DATA IN VARCHAR2, --原始数据
I IN NUMBER, --整数位数最大允许值
J IN NUMBER  --小数位数最大允许值 0-不能有小数位 ，-1 不校验小数长度
)
RETURN INTEGER
AS
V_NUMBER    NUMBER;
V_XIAOSHU   VARCHAR2 (128);
--数据类型校验 返回1 ：正确 返回0： 错误
BEGIN
IF (INSTR (IN_DATA,
',',
1,
1) <> 0)
THEN
RETURN 0;
END IF;

IF J = -1
THEN
V_XIAOSHU := '9999999999999999999999999999';
ELSIF J = 0
THEN
V_XIAOSHU := '0';
ELSE
V_XIAOSHU := TRIM (LPAD (' ', J + 1, '9'));
END IF;

V_NUMBER :=
TO_NUMBER (IN_DATA, TRIM (LPAD (' ', I + 1, '9')) || '.' || V_XIAOSHU); --利用类型转换异常判断是否合法
RETURN 1;
EXCEPTION
WHEN OTHERS
THEN
RETURN 0;
END IS_NUMBER;

--查询不是数字的字段
SELECT * FROM (SELECT ID,IS_NUMBER(TEST_VAL,20,20) A FROM TEST_TO_NUMBER) WHERE A = '0';