SQL约束minvalue/maxvalue？

Question

有没有办法为数值字段设置SQL约束,最小值应为1234,最大值应为4523？

Answer 1

对于SQL Server语法的check约束:

create table numbers (
    number int not null
        check(number >= 1234 and number <= 4523),
    ...
)

create table numbers (
    number int not null,
    check(number >= 1234 and number <= 4523),
    ...
)

create table numbers (
    number int not null,
    constraint number_range_check
        check(number >= 1234 and number <= 4523),
    ...
)

Answer 2

CREATE TABLE WhatEver
(
    ...
    NumericField INTEGER NOT NULL CHECK(NumericField BETWEEN 1234 AND 4523),
    ...
);

请注意,'BETWEEN AND'提供包含引用限制值的范围.