使用PL / SQL代替普通的SQLinsert ... select语句(通常会更快,更高效)是否真的有充分的理由? 循环是一个糟糕的选择。 只需做一个insert into target_table (col1, col2, col3) select c1, c2, c3 from source_table,它将更快 PL / SQL对循环中的迭代次数没有任何实际限制。 我无法证明这一点,但这...
PL-SQL also has FOR LOOP facility. Basically for loop in PL_SQL are of two types. First is Numerical for loop and the second one is Curser for a loop. SO in this post, we will focus mainly on Numerical for a loop. So, FOR LOOP enable us to iterate any statement or statements in...
The FOR Loop can also loop in reverse. For example: 译:FOR循环也可以反向循环(这里就是计数器从高到低),如: FOR Lcntr IN REVERSE 1..15 LOOP LCalc := Lcntr * 31; END LOOP; This example will loop 15 times. The counter will start at 15 and end at 1. (loops backwards) 译:该示例...
In Oracle, the FOR LOOP allows you to execute code repeatedly for a fixed number of times.Syntax The syntax for the FOR Loop in Oracle/PLSQL is: FOR loop_counter IN [REVERSE] lowest_number..highest_number LOOP {...statements...} END LOOP; Parameters or Arguments loop_counter The loop...
1) PL/SQL cursor FOR LOOP example# The following example declares an explicit cursor and uses it in the cursorFOR LOOPstatement. DECLARECURSORc_productISSELECTproduct_name, list_priceFROMproductsORDERBYlist_priceDESC;BEGINFORr_productINc_productLOOPdbms_output.put_line( r_product.product_name ||...
This Oracle tutorial explains how to use the CURSOR FOR LOOP in Oracle with syntax and examples. The syntax for the CURSOR FOR Loop in Oracle / PLSQL is:
For loop: counter IN 1..5 : For Loop « PL SQL « Oracle PL / SQLOracle PL / SQL PL SQL For Loop For loop: counter IN 1..5 SQL> SQL> SET SERVEROUTPUT ON SQL> DECLARE 2 counter INTEGER := 2; 3 BEGIN 4 FOR counter IN 1..5 LOOP 5 DBMS_OUTPUT.PUT_LINE(counter); 6...
[Chapter 7] 7.7 Tips for PL/SQL LoopsSteven Feuerstein &Bill Pribyl
Do not declare the loop index variable (year_ind in the example above). PL/SQL does that for you automatically. For both numeric and cursor FOR loops, the identifier after the FOR keyword is automatically declared by PL/SQL with type BINARY_INTEGER or a record to match the cursor. If yo...
I want to iterate through a list of key values and run SQL in each iteration based on that value but im not sure how to use the for loop in SQL. Something...