The method of assigning the query result of Mysql stored procedure to the variable
Assigning the query result to a variable is done using a cursor in most cases, but if you know that the query result has only one row (such as the number of statistics records, the sum of a field, etc.), you can actually use set or into to achieve assignment . Sample code:
01 drop table if exists test_tbl; 02 create table test_tbl (name varchar(20), status int(2)); 03 insert into test_tbl values('abc', 1),('edf', 2),('xyz', 3); 04 05 drop procedure IF EXISTS pro_test_3; 06 delimiter // 07 create procedure pro_test_3() 08 begin 09 -- way 1 10 DECLARE cnt INT DEFAULT 0; 11 select count(*) into cnt from test_tbl; 12 select cnt; 13 14 -- Method 2 15 set @cnt = (select count(*) from test_tbl); 16 select @cnt; 17 18 -- way 3 19 select count(*) into @cnt1 from test_tbl; 20 select @cnt1; 21 22 -- In the case of multiple columns, it seems that only the into method can be used 23 select max(status), avg(status) into @max, @avg from test_tbl; 24 select @max, @avg; 25 end 26 // 27 delimiter ; 28 29 call pro_test_3();