/* Open up a cursor for loop, also selecting * the "p" function which will write rows to * t2 for every row fetched from t1. */ FOR crec IN (Select tcol, p(tcol) FROM t1) LOOP -- Break out of the loop immediately EXIT; END LOOP; END; / Select COUNT(*) FROM t2; 注意:%...
/* Open up a cursor for loop, also selecting * the "p" function which will write rows to * t2 for every row fetched from t1. */ FOR crec IN (Select tcol, p(tcol) FROM t1) LOOP -- Break out of the loop immediately EXIT; END LOOP; END; / Select COUNT(*) FROM t2; 注意:%...
这里严格按照显示游标的书写规则:DECLARE emp_cursor定义游标OPEN emp_cursor打开游标FETCH emp_cursor INTO...提取数据CLOSE emp_cursor关闭游标,因为提取出来的数据属于多行,所以通过loop循环打印即可。 Example2:检验游标是否打开,如果打开显示提取行数 DECLARE CURSOR emp_cursor IS SELECT empno,ename,job FROM emp;...
TRUNCATE TABLE loop_test; DECLARE CURSOR ao_cur IS Select SUBSTR(object_name,1,5) FIRSTFIVE FROM all_objs Where SUBSTR(object_name,1,5) BETWEEN 'A' AND 'M'; ao_rec ao_cur%ROWTYPE; BEGIN OPEN ao_cur; LOOP FETCH ao_cur INTO ao_rec; EXIT WHEN ao_cur%NOTFOUND; Insert INTO loop_...
// fetch again. 下面做一个很简单的实验解释这个bug。 准备脚本test1.sql: DECLARE cursor c1 is select rowid from test1 where ROWNUM <= 50000; cnt number(38); begin cnt := 0; for c1rec in c1 loop delete from test1 where rowid = c1rec.rowid; ...
13.2.2 游标中的loop语句 13.2.3 使用bulk collect和for语句的游标游标中通常使用fetch into 语句提取数据,这种方式是单条数据提取,但是在数据量很大的情况下执行效率不是很理想。而此时引用fetch bulk collect into语句可以批量提取数据,在数据量大的情况下它的执行效率比单条提取数据的高。语法如图所示。 13.2.3 使...
Perform a cursor for loop that will populate the Oracle Object RIB_ROUTINGINFO_TBL. Function Level Description – GET_NOT_BEFORE_DAYS (local) This function checks if the variable (LP_nbf_days) has a value or not. If not, it will populate the variable based on code_detail and then ...
(SELECT * FROM t1) LOOP n := n + 1; OPEN c_chk (c.col); FETCH c_chk INTO chk; IF c_chk%FOUND THEN UPDATE lossytable SET freq = freq + 1 WHERE val = c.col; ELSE INSERT INTO lossytable (val, freq, bk) VALUES (c.col, 1, b-1); END IF; IF n MOD Bktsize = 0 ...
OPEN_CURSOR PARSE BIND_VARIABLE EXECUTE FETCH_ROWS CLOSE_CURSOR 使用DBMS_SQL执行DML语句 删除行的例子 CREATEORREPLACEFUNCTIONdelete_all_rows(table_nameVARCHAR2)RETURNNUMBERIScsr_idINTEGER;rows_delNUMBER;BEGINcsr_id:=DBMS_SQL.OPEN_CURSOR;DBMS_SQL.PARSE(csr_id,'DELETE FROM '||table_name,DBMS_SQL...
当value值列表中有一个为NULL,则返回NULL值。 EXAMPLE: select greatest (1, 3, 2 ) from dual ; — 返回3 select greatest ( 'A’, 'B’, 'C’ ) from dual ; — 返回C select greatest (null, 'B’, 'C’ ) from dual ; — 返回null ...