ROUND()

    1. > drop table if exists t1;
    2. > create table t1(a int ,b float);
    3. > insert into t1 values(1,0.5);
    4. > insert into t1 values(2,0.499);
    5. > insert into t1 values(3,0.501);
    6. > insert into t1 values(4,20.5);
    7. > insert into t1 values(5,20.499);
    8. > insert into t1 values(6,13.500);
    9. > insert into t1 values(7,-0.500);
    10. > insert into t1 values(8,-0.499);
    11. > insert into t1 values(9,-0.501);
    12. > insert into t1 values(10,-20.499);
    13. > insert into t1 values(11,-20.500);
    14. > insert into t1 values(12,-13.500);
    15. > select a,round(b) from t1;
    16. +------+----------+
    17. | a    | round(b) |
    18. |    1 |   0.0000 |
    19. |    2 |   0.0000 |
    20. |    3 |   1.0000 |
    22. |    5 |  20.0000 |
    23. |    6 |  14.0000 |
    24. |    7 |  -0.0000 |
    25. |    8 |  -0.0000 |
    26. |    9 |  -1.0000 |
    27. |   10 | -20.0000 |
    28. |   11 | -20.0000 |
    29. |   12 | -14.0000 |
    30. +------+----------+
    31. > select a,round(b,-1) from t1;
    32. +------+--------------+
    33. | a    | round(b, -1) |
    34. +------+--------------+
    35. |    1 |       0.0000 |
    36. |    2 |       0.0000 |
    37. |    3 |       0.0000 |
    38. |    4 |      20.0000 |
    39. |    5 |      20.0000 |
    40. |    7 |      -0.0000 |
    41. |    8 |      -0.0000 |
    43. |   10 |     -20.0000 |
    44. |   11 |     -20.0000 |
    45. |   12 |     -10.0000 |
    46. +------+--------------+
    47. > select round(a*b) from t1;
    48. +--------------+
    49. | round(a * b) |
    50. +--------------+
    51. |       0.0000 |
    52. |       1.0000 |
    53. |       2.0000 |
    54. |      82.0000 |
    55. |     102.0000 |
    56. |      81.0000 |
    57. |      -4.0000 |
    58. |      -4.0000 |
    59. |      -5.0000 |
    60. |    -205.0000 |
    61. |    -226.0000 |
    62. +--------------+

    MatrixOne目前只支持在查询表的时候使用函数，不支持单独使用函数。