postgresql 函數擷取多個欄位的數字大小值

標籤：

1、GREATEST(n1,n2,n3,..........) 擷取最大值

testdb=#SELECT GREATEST(3,5,1,8,33,99,34,55,67,43); +---------------------------------------------------------+ | GREATEST(3,5,1,8,33,99,34,55,67,43)                     | +---------------------------------------------------------+ | 99                                                      | +---------------------------------------------------------+ 1 row in set (0.00 sec) 

2、LEAST(N1,N2,N3,N4,......) 擷取最小值

testdb=#SELECT LEAST(3,5,1,8,33,99,34,55,67,43); +---------------------------------------------------------+ | LEAST(3,5,1,8,33,99,34,55,67,43)                        | +---------------------------------------------------------+ | 1                                                       | +---------------------------------------------------------+ 1 row in set (0.00 sec) 

其他更多函數參考：http://developer.51cto.com/art/201401/426252_all.htm

 

postgresql 函數擷取多個欄位的數字大小值