-- first we'll pull some records out of our table. DECLARE CursorQuery CURSOR FOR SELECT ID FROM myTable WHERE MyRecord > 15 OPEN CursorQuery -- we're going to fetch our record into the ID variable which we'll use for inserting a related record. FETCH NEXT FROM CursorQuery INTO @ID...
The PL/SQL FOR LOOP statement has the following structure: FOR index IN lower_bound .. upper_bound LOOP statements; END LOOP;Code language: SQL (Structured Query Language) (sql) The index is an implicit variable. It is local to the FOR LOOP statement. In other words, you cannot ...
Is there a way I can sort of close out of the query, enter the id variable, and resume the sql query with mysql.connector? This is what it looks like right now: for i in range(1, 2642): habe = mysql.connector.connect( host="localhost", user="root", passwd="", data...
WITH RECURSIVE recursive_query AS ( SELECT * FROM table_name WHERE parent_id IS NULL UNION ALL SELECT t.* FROM table_name t JOIN recursive_query r ON t.parent_id = r.id ) SELECT * FROM recursive_query; 复制代码 总的来说,for循环适用于需要对每条记录进行相同处理的情况,而递归查询适用于...
MySQL不支持FOR loops循环。只有LOOP循环：[begin_label:] LOOP statement_list END LOOP [end_label]CREATE PROCEDURE doiterate(p1 INT)BEGIN label1: LOOP SET p1 = p1 + 1;IF p1 < 10 THEN ITERATE label1;END IF;LEAVE label1;END LOOP label1;SET @x = p1;END;LOOP实现了一个简单的...
'||CURRENT_VALUE;ENDIF;ELSECONDITIONS :=CONDITIONS||' = '||ALIAS||'.'||CURRENT_VALUE||' ';ENDIF;--循环值减1SIGNS :=SIGNS-1;ENDLOOP;--拼接关联SQLTARGET_RESULTS :=TARGET_RESULTS||'LEFT JOIN (SELECT DISTINCT '||QUERY_ITEMS||','||TEMP.QUERY_CONTENT||' AS A'||TEMP.ID||' FROM ...
forxin(select*from rollup)loopif(notexists(that query))thenOUTPUTendif;end loop; 注意:NOT EXISTS 与 NOT IN 不能完全互相替换,看具体的需求。如果选择的列可以为空,则不能被替换。 例如下面语句,看他们的区别: 代码语言:javascript 代码运行次数:0 ...
ID || '.' || CURRENT_VALUE; --拼接查询字符串 QUERY_ITEMS := QUERY_ITEMS || ',' || CURRENT_VALUE; END IF; ELSE CONDITIONS := CONDITIONS || ' = ' || ALIAS || '.' || CURRENT_VALUE || ' '; END IF; --循环值减1 SIGNS := SIGNS - 1; END LOOP; --拼接关联SQL TARGET_...
l_emp_ids emp_id_tbl ;BEGINSELECTemp_idBULKCOLLECTINTOl_emp_idsFROMemp;FORiINl_emp_ids .FIRST .. l_empnos.LAST LOOP dbms_output.put_line( l_emp_ids (i) );ENDLOOP;END; LOOP TO DELETE declarel_sqlvarchar2(500);--variable that contains a queryl_c sys_refcursor;--cursor variable...
FOR…IN 通过一个查询的结果进行迭代并且操纵相应的数据。语法是: [ <> ] FOR target IN query LOOP statements END LOOP [ label ]; 1. 2. 3. 4. target是一个记录变量、行变量或者逗号分隔的标量变量列表。target被连续不断被赋予来自query的每一行,并且循环体将为每一行执行一次。下面是一个例子: creat...