1 numeric 是 number 的一种子类型，用户表示定点数Use the subtypes DEC, DECIMAL, and NUMERIC to declare fixed-point numbers with a maximum precision of 38 decimal digits.2 Number(1,0)最多能表示的数字范围为-9至93 如果合适的话用 SIGNTYPE 类型，表示范围为-1, 0, and 1SIGNTYPE lets you restrict an integer variable to the values -1, 0, and 1, which is useful in programming tri-state logic.
a maximum precision of 38 decimal digits.2 Number(1,0)最多能表示的数字范围为-9至93 如果合适的话用 SIGNTYPE 类型，表示范围为-1, 0, and 1SIGNTYPE lets you restrict an integer variable to the values -1, 0, and 1, which is useful in programming tri-state logic.