DO $$DECLAREprod_rec RECORD; prod_cursorCURSORFORSELECT*FROMproducts;BEGINOPENprod_cursor; LOOPFETCHprod_cursorINTOprod_rec;EXITWHENNOTFOUND;--Example processing: Print the name and priceRAISE NOTICE'Product: %, Price: %', prod_rec.name, prod_rec.price;ENDLOOP;CLOSEprod_cursor;END$$; 🧭 Cursor Control Commands
CURSOR <游标名称> IS <游标名称>%ROWTYPE; BEGIN OPEN <游标名称> LOOP FETCH <游标名称> INTO ; EXIT WHEN <游标名称>%NOTFOUND; <其它要执行的代码> END LOOP; CLOSE <游标名称>; END <存储过程名称>; / 代码例子: 复制内容到剪贴板 程序代码 TRUNCATE TABLE loop_test; DECLARE CURSOR ao_cur IS ...
which creates a portal given a prepared statement and values for any needed parameters; and an execute step that runs a portal's query. In the case of a query that returns rows (SELECT, SHOW, etc), the execute step can be told to fetch only...
使用cursor.execute 和SQL SELECT 语句来读取数据。 cursor.fetchall() 用于接受查询并返回结果集以进行迭代。 Python 复制 # Fetch all rows from table cursor.execute("SELECT * FROM pharmacy;") rows = cursor.fetchall() # Print all rows for row in rows: print("Data row = (%s, %s)" %(str...
FETCH FROM c3 INTO rowvar; EXIT WHEN NOT FOUND; END LOOP; CLOSE c3; END$$; Example of MOVE a cursor without fetching data MOVErepositions a cursor without retrieving any data and works such as theFETCHcommand, except it only repositions the cursor in the dataset and doesn...
The query might be suspended during execution. In any situation in which the system thinks that partial or incremental execution might occur, no parallel plan is generated. For example, a cursor created using DECLARE CURSOR will never use a parallel plan. Similarly, a PL/pgSQL loop of the fo...
有各种服务器参数会影响 Azure Cosmos DB for PostgreSQL 的行为,无论是来自标准 PostgreSQL 还是特定于 Azure Cosmos DB for PostgreSQL。 可以在 Azure 门户中为群集设置这些参数。 在“设置”类别下,选择“工作器节点参数”或“协调器节点参数” 。 在这些页面中可为所有工作器节点设置参数,或者只是为协调器节点...
*/ // 可能在这里执行查询 PortalStart(portal, NULL, 0, InvalidSnapshot); /* * Select the appropriate output format: text unless we are doing a * FETCH from a binary cursor. (Pretty grotty to have to do this here * --- but it avoids grottiness in other places. Ah, the joys of ...
example, “a + b” (one OpExpr, with two Var expressions) would be represented as two steps to fetch the Var values, and one step for the evaluation of the function underlying the + operator. The steps for the Vars would have their resvalue/resnull pointing directly to the appropriate ...
*/DBMS_SQL.BIND_ARRAY(c,':dept_array', dept_no_array,1,4);/* Bind only elements 1 through 4 to the cursor Happens 4 times */dummy :=DBMS_SQL.EXECUTE(c);/* Execute the Query, and return number of rows deleted! */DBMS_SQL.CLOSE_CURSOR(c); ...