EXPLAIN works with SELECT, DELETE, INSERT, REPLACE, and UPDATE statements. EXPLAIN与SELECT、DELETE、INSERT、REPLACE和UPDATE语句一起工作。 When EXPLAIN is used with an explainable statement, MySQL displays information from the optimizer about the statement execution plan. That is, MySQL explains how it...
:=counter+customIncrement;--自定义递增值SET@key3:=CONCAT('Key3_',FLOOR(RAND()*1000));SET@key_part1:=CONCAT('Key_Part1_',FLOOR(RAND()*1000));SET@key_part2:=CONCAT('Key_Part2_',FLOOR(RAND()*1000));SET@key_part3:=CONCAT('Key_Part3_',FLOOR(RAND()*1000));SET@common_field:=...
(100) DEFAULT 'abcdefghijklmnopqrstuvwxyzABCDEFJHIJKLMNOPQRSTUVWXYZ'; DECLARE return_str VARCHAR(255) DEFAULT ''; DECLARE i INT DEFAULT 0; WHILE i < n DO SET return_str =CONCAT(return_str,SUBSTRING(chars_str,FLOOR(1+RAND()*52),1)); SET i = i + 1; END WHILE; RETURN return_str;...
do { printf("%d",i); i--; }while(i>=0); where 'i' is the loop variable. Answer and Explanation:1 Both for loop and while loop can run multiple statements in successive repetition efficiently. Considerations: The 'While' loop is implemented in... ...
do $$declarev_idxinteger:=1;beginwhile v_idx<6000000loop v_idx=v_idx+1;insertintotest2 (name, category_id)values( random()*(20000000000000000-10)+10,random()*(6000000-10)+10);endloop;end$$; 验证下查询 explainselecta.id,b.idfromtest1 a,test2 bwherea.category_id=b.category_idanda....
drop procedure if exists insert_emp;delimiter ;;create procedure insert_emp()begindeclare i int;set i=1;while(i<=100000)doinsert into employees(name,age,position) values(CONCAT('zhenghuisheng',i),i,'dev');set i=i+1;end while;end;;delimiter ;call insert_emp(); ...
I've got following code I want to execute the query first and then return result. How should I do it. I've also done it with simple for loop but does not work. I think you just need to call next() aft... what is the difference between \c and \\c?
SUCCESS: RETURN 0 FAIL: RETURN -200 while表达式 while 条件表达式 do 逻辑体; end while; LOOP表达式 LOOP... END LOOP;例: OPEN c1; ins_loop: LOOP FETCH c1 INTO v_dept, v_deptname, v_admdept; IF at_end = 1 THEN LEAVEins_loop; --中断循环 ELSEIF v_dept = 'D11' THEN ITERATEins...
WHILE i < n DO SET return_str =CONCAT(return_str,SUBSTRING(chars_str,FLOOR(1+RAND()*52),1)); SET i = i + 1; END WHILE; RETURN return_str; END // DELIMITER ; 创建存储过程 创建往s1表中插入数据的存储过程: DELIMITER // CREATE PROCEDURE insert_s1 (IN min_num INT (10),IN max_...
Do Loops Explain Consciousness? Review of [Am a Strange LoopOur brain is a small lump of organic molecules. It contains some hundred billion neurons, each more complex than a galaxy. They are connected in over a million billion ways. By what incredible hocus-pocus does this tangle of ...