taos> select TRUNCATE(10.55, 3)
    truncate(10.55, 3)     |
============================
                     10.55 |

taos> select TRUNCATE(10.55, 2)
    truncate(10.55, 2)     |
============================
                     10.55 |

taos> select TRUNCATE(10.55, 1)
    truncate(10.55, 1)     |
============================
                      10.5 |

taos> select TRUNCATE(10.55, 0)
    truncate(10.55, 0)     |
============================
                        10 |

taos> select TRUNCATE(10.55, -1)
    truncate(10.55, -1)    |
============================
                        10 |

taos> select TRUNCATE(10.55, -10)
   truncate(10.55, -10)    |
============================
                         0 |

taos> select TRUNCATE(-10.55, 1)
    truncate(-10.55, 1)    |
============================
                     -10.5 |

taos> select TRUNCATE(99, 1)
    truncate(99, 1)    |
========================
                    99 |

taos> select TRUNCATE(10.55, 1) + 1
  truncate(10.55, 1) + 1   |
============================
                      11.5 |

taos> select TRUNCATE(TRUNCATE(TRUNCATE(TRUNCATE(TRUNCATE(TRUNCATE(TRUNCATE(123.123456789, 9), 8), 7), 6), 5), 4), 3)
 truncate(truncate(truncate(truncate(truncate(truncate(truncate(1 |
===================================================================
                                                         123.123 |

taos> select TRUNCATE(TRUNCATE(TRUNCATE(TRUNCATE(TRUNCATE(TRUNCATE(TRUNCATE(123456789.123456789, -1), -2), -3), -4), -5), -6), -7)
 truncate(truncate(truncate(truncate(truncate(truncate(truncate(1 |
===================================================================
                                                       120000000 |

taos> select TRUNCATE(87654321.123456789, id) from ts_4893.meters order by ts limit 10
 truncate(87654321.123456789, id) |
===================================
                         87654321 |
                       87654321.1 |
                      87654321.12 |
                     87654321.123 |
                    87654321.1234 |
                   87654321.12345 |
                  87654321.123456 |
                 87654321.1234567 |
                 87654321.1234568 |
                 87654321.1234568 |

taos> select TRUNCATE(current, id) from ts_4893.meters order by ts limit 10
 truncate(current, id) |
========================
                    10 |
                   8.5 |
                  9.79 |
                11.233 |
                10.706 |
                 8.508 |
                 9.596 |
                10.962 |
                11.226 |
                10.337 |

taos> select TRUNCATE(current, 1) from ts_4893.meters order by ts limit 10
 truncate(current, 1) |
=======================
                 10.6 |
                  8.5 |
                  9.7 |
                 11.2 |
                 10.7 |
                  8.5 |
                  9.5 |
                 10.9 |
                 11.2 |
                 10.3 |

taos> select TRUNC(10.55, 3)
      trunc(10.55, 3)      |
============================
                     10.55 |

taos> select TRUNC(10.55, 2)
      trunc(10.55, 2)      |
============================
                     10.55 |

taos> select TRUNC(10.55, 1)
      trunc(10.55, 1)      |
============================
                      10.5 |

taos> select TRUNC(10.55, 0)
      trunc(10.55, 0)      |
============================
                        10 |

taos> select TRUNC(10.55, -1)
     trunc(10.55, -1)      |
============================
                        10 |

taos> select TRUNC(10.55, -10)
     trunc(10.55, -10)     |
============================
                         0 |

taos> select TRUNC(-10.55, 1)
     trunc(-10.55, 1)      |
============================
                     -10.5 |

taos> select TRUNC(99, 1)
     trunc(99, 1)      |
========================
                    99 |

taos> select TRUNC(10.55, 1) + 1
    trunc(10.55, 1) + 1    |
============================
                      11.5 |

taos> select TRUNC(TRUNC(TRUNC(TRUNC(TRUNC(TRUNC(TRUNC(123.123456789, 9), 8), 7), 6), 5), 4), 3)
 trunc(trunc(trunc(trunc(trunc(trunc(trunc(123.123456789, 9), 8), |
===================================================================
                                                         123.123 |

taos> select TRUNC(TRUNC(TRUNC(TRUNC(TRUNC(TRUNC(TRUNC(123456789.123456789, -1), -2), -3), -4), -5), -6), -7)
 trunc(trunc(trunc(trunc(trunc(trunc(trunc(123456789.123456789, - |
===================================================================
                                                       120000000 |

taos> select TRUNC(87654321.123456789, id) from ts_4893.meters order by ts limit 10
 trunc(87654321.123456789, id) |
================================
                      87654321 |
                    87654321.1 |
                   87654321.12 |
                  87654321.123 |
                 87654321.1234 |
                87654321.12345 |
               87654321.123456 |
              87654321.1234567 |
              87654321.1234568 |
              87654321.1234568 |

taos> select TRUNC(current, id) from ts_4893.meters order by ts limit 10
  trunc(current, id)  |
=======================
                   10 |
                  8.5 |
                 9.79 |
               11.233 |
               10.706 |
                8.508 |
                9.596 |
               10.962 |
               11.226 |
               10.337 |

taos> select TRUNC(current, 1) from ts_4893.meters order by ts limit 10
  trunc(current, 1)   |
=======================
                 10.6 |
                  8.5 |
                  9.7 |
                 11.2 |
                 10.7 |
                  8.5 |
                  9.5 |
                 10.9 |
                 11.2 |
                 10.3 |

taos> select truncate(99.99, 3)
    truncate(99.99, 3)     |
============================
                     99.99 |

taos> select truncate(99.99, 2)
    truncate(99.99, 2)     |
============================
                     99.99 |

taos> select truncate(99.99, 1)
    truncate(99.99, 1)     |
============================
                      99.9 |

taos> select truncate(99.99, 0)
    truncate(99.99, 0)     |
============================
                        99 |

taos> select truncate(99.99, -1)
    truncate(99.99, -1)    |
============================
                        90 |

taos> select truncate(99.99, -10)
   truncate(99.99, -10)    |
============================
                         0 |

taos> select truncate(99, 1)
    truncate(99, 1)    |
========================
                    99 |

taos> select truncate(current, 1) from ts_4893.d0 order by ts limit 10
 truncate(current, 1) |
=======================
                 10.6 |
                  8.5 |
                  9.7 |
                 11.2 |
                 10.7 |
                  8.5 |
                  9.5 |
                 10.9 |
                 11.2 |
                 10.3 |

taos> select truncate(current, 1) from ts_4893.meters order by ts limit 10
 truncate(current, 1) |
=======================
                 10.6 |
                  8.5 |
                  9.7 |
                 11.2 |
                 10.7 |
                  8.5 |
                  9.5 |
                 10.9 |
                 11.2 |
                 10.3 |

taos> select truncate(99.99, null)
   truncate(99.99, null)   |
============================
 NULL                      |

taos> select truncate(null, 3)
 truncate(null, 3) |
====================
 NULL              |

taos> select truncate(1.0001, 3)
    truncate(1.0001, 3)    |
============================
                         1 |

taos> select truncate(2.71828, 4)
   truncate(2.71828, 4)    |
============================
                    2.7182 |

taos> select truncate(3.14159, 2)
   truncate(3.14159, 2)    |
============================
                      3.14 |

taos> select truncate(100.9876, 2)
   truncate(100.9876, 2)   |
============================
                    100.98 |

taos> select truncate(99999999999999.9999, 2)
 truncate(99999999999999.9999, 2) |
===================================
                  100000000000000 |

taos> select truncate(-5.678, 2)
    truncate(-5.678, 2)    |
============================
                     -5.67 |

taos> select truncate(voltage, 2) from ts_4893.meters limit 1
 truncate(voltage, 2) |
=======================
                  221 |

taos> select truncate(current, 1) from ts_4893.meters limit 1
 truncate(current, 1) |
=======================
                 10.6 |

taos> select truncate(phase, 3) from ts_4893.meters limit 1
  truncate(phase, 3)  |
=======================
                0.508 |

taos> select truncate(voltage + current, 2) from ts_4893.meters limit 1
 truncate(voltage + current, 2) |
=================================
                         231.64 |

taos> select truncate(voltage, -1) from ts_4893.meters limit 1
 truncate(voltage, -1) |
========================
                   220 |

taos> select round(truncate(voltage, 1), 2) from ts_4893.meters limit 1
 round(truncate(voltage, 1), 2) |
=================================
                            221 |

taos> select truncate(abs(current), 1) from ts_4893.meters limit 1
 truncate(abs(current), 1) |
============================
                      10.6 |

taos> select truncate(exp(phase), 2) from ts_4893.meters limit 1
  truncate(exp(phase), 2)  |
============================
                      1.66 |

taos> select truncate(log(current), 1) from ts_4893.meters limit 1
 truncate(log(current), 1) |
============================
                       2.3 |