Oracle vertical table to horizontal table

Assume that the following vertical table exists. The first column is the ID of a business data, the second column is the type, and the third column is the value corresponding to the type, for example:

As shown in the preceding table, there are three types: 2, 3, and 4. The three types of business data Id 1 have values, and the three types of business data ID 2 have values, if the business data ID is 3, only Type 2 and 3 have values. to display the vertical table horizontally, you can use the followingCode:

-- ===================================================== =============================-- Change the vertical table to a horizontal table: -- 1. conversion type. The type value must be an integer and not equal to 0. That is, 0 is meaningless, 0 can be expressed as null -- ============================================ ===================================== select T. ID, sum (decode (T. code, 2, 2, 0) "second", -- if the row type is 2, it is 2, and the others are 0 sum (decode (T. code, 3, 3, 0) "third item", sum (decode (T. code, 4, 4, 0) "fourth item" from TTT t where T. id = 1 group by T. ID; -- ===================================================== =============================-- change the vertical table to a horizontal table: -- 1. the data corresponding to the conversion type, and the data must be a numerical value, and 0 is meaningless, that is, 0 can be expressed as null -- ==================================== ======================================= select T. ID, sum (decode (T. code, 2, T. val, 0) "second", -- if the row type is 2, the decode value corresponding to type 2 is displayed; otherwise, the value 0 sum (decode (T. code, 3, T. val, 0) "third", sum (decode (T. code, 4, T. val, 0) "fourth" from ttt t group by T. ID;