mysql:ytt>desc selectcount(*)from t1 a join t1 b on a.r1=b.r1\G***1.row***id:1select_type:SIMPLEtable:apartitions:NULLtype:indexpossible_keys:idx_r1key:idx_r1key_len:5ref:NULLrows:2552706filtered:100.00Extra:Usingwhere;Using index***2.row***id:1select_type:SIMPLEtable:bpartitions...
So now, all the IsPaid field of the details table was set to true. Question: How can I loop through each row in the Details table and check whether the IsPaid field is already true? if all rows were true, how can I update the IsPaid field of the Header table? Thank you all for...
Now, let us convert the above example toWHILE loop. To convert a cursor to while loop, first you have to find the total number of rows in the table. Then you have to iterate through the table rows using WHILE control-of-flow element till the total row count is reached. Here is how ...
declare type row_num_type is table of number index by simple_integer; type row_text_type is table of varchar2(10) index by simple_integer; row_num_tab row_num_type; row_text_tab row_text_type; v_total number;begin for i in 1..10 loop row_num_tab(i) := i; row_text_tab(i)...
Add Time in SQL HH:MM:SS to another HH:MM:SS Adding a column to a large (100 million rows) table with default constraint adding a extra column in a pivot table created uisng T-SQL Pivot Table query Adding a partition scheme to an existing table. Adding a Value to a 'date' Column...
GetRow() 方法會傳回一列資料,而呼叫其的次數會在透過圖形和 XML 執行程序表所產生的執行程序表輸出中顯示為 ActualRows。 如需這些 SET 選項的詳細資訊,請參閱 SET STATISTICS PROFILE (Transact-SQL) 與SET STATISTICS XML (Transact-SQL)。 執行程序表輸出中顯示的 ActualRebinds 和ActualRewinds 計數...
is_open (infile) THEN -- loop through each line in the file LOOP BEGIN UTL_FILE.get_line (infile, vnewline); -->从源文件读取行 i := UTL_FILE.fgetpos (infile); -->将行的位置赋值并输出 DBMS_OUTPUT.put_line (TO_CHAR (i)); UTL_FILE.put_line (outfile, vnewline, FALSE); --...
Tips:不要见了in就改成exists,其实in和exists如果没有产生filter,都属于半连接。用到连接的话就要分析连接方式和顺序了,其实产生filter相当于执行计划被固化成嵌套循环,类似驱动表固定为in子表的nestloop。 17. rows 指定表或结果集返回多少行 EXPLAIN select /*+ rows(e #100) */ * from emp e; ...
--CREATE a table to store the results CREATE TABLE IF NOT EXISTS ordertotals (order_num INT, total DECIMAL(8,2)); --Open the cursor OPEN ordernumbers; --Loop through all rows REPEAT --GET order number FETCH ordernumbers INTO o; --Get the total for this order CALL ordertotal(o,1,...
-- Declare a handler for cursor termination DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1; -- Open the cursor OPEN studentCursor; -- Fetch rows and loop through REPEAT FETCH studentCursor INTO studentID, studentName; IF NOT done THEN ...