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Find “greatest” between two columns and display with some records already null in MySql
Let us first create a table −
mysql> create table DemoTable -> ( -> Value1 int, -> Value2 int -> ); Query OK, 0 rows affected (0.77 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable values(78,89); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(19,null); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values(null,0); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable values(null,95); Query OK, 1 row affected (0.15 sec)
Display all records from the table using select statement −
mysql> select *from DemoTable;
This will produce the following output −
+--------+--------+ | Value1 | Value2 | +--------+--------+ | 78 | 89 | | 19 | NULL | | NULL | 0 | | NULL | 95 | +--------+--------+ 4 rows in set (0.00 sec)
Here is the query to find the “greatest” from two columns −
mysql> select greatest(if(Value1 is null,0,Value1),if(Value2 is null,0,Value2)) from DemoTable;
This will produce the following output −
+-------------------------------------------------------------------+ | greatest(if(Value1 is null,0,Value1),if(Value2 is null,0,Value2)) | +-------------------------------------------------------------------+ | 89 | | 19 | | 0 | | 95 | +-------------------------------------------------------------------+ 4 rows in set (0.00 sec)
Updated on: 12-Dec-2019
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