SQL ROUND() 函数
SQL ROUND() 函数用于把数值四舍五入为指定的小数位数
SELECT ROUND( column_name ,decimals) FROM table_name;
| 参数 | 描述 |
|---|---|
| column_name | 必需。要舍入的数值或字段 |
| decimals | 可选。设置要返回的小数位数。默认为 0 |
注意：ROUND() 返回值会被转换为 BIGINT 类型
SQL ROUND() 示例
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ROUND(X)
ROUND(X)返回参数X的四舍五入的一个整数mysql> SELECT ROUND(-1.23); +--------------+ | ROUND(-1.23) | +--------------+ | -1 | +--------------+ 1 row in set (0.00 sec) mysql> SELECT ROUND(-1.58); +--------------+ | ROUND(-1.58) | +--------------+ | -2 | +--------------+ 1 row in set (0.00 sec) mysql> SELECT ROUND(1.58); +-------------+ | ROUND(1.58) | +-------------+ | 2 | +-------------+ 1 row in set (0.00 sec)
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ROUND(X,D)
ROUND(X,D)返回参数 X的四舍五入为 D 位小数的一个数字如果
D为0，结果将没有小数点或小数部分mysql> SELECT ROUND(1.298, 1); +-----------------+ | ROUND(1.298, 1) | +-----------------+ | 1.3 | +-----------------+ 1 row in set (0.00 sec) ``` mysql> SELECT ROUND(1.298, 0); +-----------------+ | ROUND(1.298, 0) | +-----------------+ | 1 | +-----------------+ 1 row in set (0.00 sec)
注意：ROUND() 返回值会被转换为 BIGINT 类型